[{"data":1,"prerenderedAt":1290},["ShallowReactive",2],{"navigation_docs":3,"-programming-javascript-data-types-type-system":30,"-programming-javascript-data-types-type-system-surround":1287},[4,9],{"title":5,"path":6,"stem":7,"icon":8},"Welcome","\u002Fhome","1.home","i-lucide-rocket",{"title":10,"icon":11,"path":12,"stem":13,"children":14,"page":29},"Programming","i-lucide-code","\u002Fprogramming","2.programming",[15],{"title":16,"icon":17,"path":18,"stem":19,"children":20,"page":29},"JavaScript","i-lucide-file-braces-corner","\u002Fprogramming\u002Fjavascript","2.programming\u002F1.javascript",[21,25],{"title":22,"path":23,"stem":24},"1. Variables & Declarations","\u002Fprogramming\u002Fjavascript\u002Fvariables-and-declarations","2.programming\u002F1.javascript\u002F1.variables-and-declarations",{"title":26,"path":27,"stem":28},"2. Data Types + Type System","\u002Fprogramming\u002Fjavascript\u002Fdata-types-type-system","2.programming\u002F1.javascript\u002F2.data-types-type-system",false,{"id":31,"title":32,"body":33,"description":1278,"extension":1279,"links":1280,"meta":1281,"navigation":1282,"path":27,"seo":1283,"stem":28,"__hash__":1286},"docs\u002F2.programming\u002F1.javascript\u002F2.data-types-type-system.md","Chapter 2: Data Types + Type System",{"type":34,"value":35,"toc":1264},"minimark",[36,41,67,71,90,95,154,189,198,216,231,236,239,313,317,344,347,428,432,437,536,549,553,558,631,635,649,686,694,698,712,734,738,743,759,766,770,787,852,856,868,872,909,913,918,1014,1019,1081,1086,1183,1202,1260],[37,38,40],"h2",{"id":39},"what-are-data-types","What are Data Types?",[42,43,44,48],"ul",{},[45,46,47],"li",{},"In JavaScript, every value has a type.",[45,49,50,51,56,57,56,60,56,63,66],{},"These types define what kind of data is being stored - ",[52,53,55],"span",{"style":54},"color: #eab308;","number",", ",[52,58,59],{"style":54},"text",[52,61,62],{"style":54},"boolean",[52,64,65],{"style":54},"object",", etc.",[68,69,70],"p",{},"There are two categories:",[42,72,73,82],{},[45,74,75,81],{},[52,76,77],{"style":54},[78,79,80],"strong",{},"Primitive types"," - stored directly",[45,83,84,89],{},[52,85,86],{"style":54},[78,87,88],{},"Reference \u002F Non-Primitive types"," - stored as memory references",[91,92,94],"h3",{"id":93},"primitive-data-types","Primitive Data Types",[96,97,98,117,134,148],"ol",{},[45,99,100,103,104,107,56,111,56,114],{},[78,101,102],{},"String"," → Text",[105,106],"br",{},[108,109,110],"code",{},"\"hello\"",[108,112,113],{},"'Shoaib'",[108,115,116],{},"`Shaikh`",[45,118,119,122,123,125,56,128,56,131],{},[78,120,121],{},"Number"," → Any numeric value",[105,124],{},[108,126,127],{},"3",[108,129,130],{},"-99",[108,132,133],{},"3.14",[45,135,136,139,140,142,56,145],{},[78,137,138],{},"Boolean"," → True or False",[105,141],{},[108,143,144],{},"true",[108,146,147],{},"false",[45,149,150,153],{},[78,151,152],{},"Undefined"," → Variable declared but not assigned",[155,156,161],"pre",{"className":157,"code":158,"language":159,"meta":160,"style":160},"language-js shiki shiki-themes material-theme-lighter material-theme material-theme-palenight","let x;\nx \u002F\u002F Output → undefined\n","js","",[108,162,163,179],{"__ignoreMap":160},[52,164,167,171,175],{"class":165,"line":166},"line",1,[52,168,170],{"class":169},"spNyl","let",[52,172,174],{"class":173},"sTEyZ"," x",[52,176,178],{"class":177},"sMK4o",";\n",[52,180,182,185],{"class":165,"line":181},2,[52,183,184],{"class":173},"x ",[52,186,188],{"class":187},"sHwdD","\u002F\u002F Output → undefined\n",[96,190,192],{"start":191},5,[45,193,194,197],{},[78,195,196],{},"Null"," → Intentional empty value",[155,199,201],{"className":157,"code":200,"language":159,"meta":160,"style":160},"let x = null;\n",[108,202,203],{"__ignoreMap":160},[52,204,205,207,210,213],{"class":165,"line":166},[52,206,170],{"class":169},[52,208,209],{"class":173}," x ",[52,211,212],{"class":177},"=",[52,214,215],{"class":177}," null;\n",[96,217,219,225],{"start":218},6,[45,220,221,224],{},[78,222,223],{},"Symbol"," → Unique identifier (rarely used)",[45,226,227,230],{},[78,228,229],{},"BigInt"," → Very large integers",[68,232,233],{},[108,234,235],{},"123456789012345678901234567n",[68,237,238],{},"These are copied directly:",[155,240,242],{"className":157,"code":241,"language":159,"meta":160,"style":160},"let a = 2;\nlet b = a;\nb = b + 1;\nb; \u002F\u002F output → 3\na; \u002F\u002F output → 2\n",[108,243,244,259,273,291,303],{"__ignoreMap":160},[52,245,246,248,251,253,257],{"class":165,"line":166},[52,247,170],{"class":169},[52,249,250],{"class":173}," a ",[52,252,212],{"class":177},[52,254,256],{"class":255},"sbssI"," 2",[52,258,178],{"class":177},[52,260,261,263,266,268,271],{"class":165,"line":181},[52,262,170],{"class":169},[52,264,265],{"class":173}," b ",[52,267,212],{"class":177},[52,269,270],{"class":173}," a",[52,272,178],{"class":177},[52,274,276,279,281,283,286,289],{"class":165,"line":275},3,[52,277,278],{"class":173},"b ",[52,280,212],{"class":177},[52,282,265],{"class":173},[52,284,285],{"class":177},"+",[52,287,288],{"class":255}," 1",[52,290,178],{"class":177},[52,292,294,297,300],{"class":165,"line":293},4,[52,295,296],{"class":173},"b",[52,298,299],{"class":177},";",[52,301,302],{"class":187}," \u002F\u002F output → 3\n",[52,304,305,308,310],{"class":165,"line":191},[52,306,307],{"class":173},"a",[52,309,299],{"class":177},[52,311,312],{"class":187}," \u002F\u002F output → 2\n",[91,314,316],{"id":315},"reference-non-primitive-data-types","Reference \u002F Non-Primitive Data Types",[96,318,319,328,336],{},[45,320,321,324,325],{},[78,322,323],{},"Object"," → ",[108,326,327],{},"{ name: \"Shoaib\", age: 22 }",[45,329,330,324,333],{},[78,331,332],{},"Array",[108,334,335],{},"[10, 20, 30]",[45,337,338,324,341],{},[78,339,340],{},"Function",[108,342,343],{},"function studentName() { }",[68,345,346],{},"These are not copied directly, but by reference:",[155,348,350],{"className":157,"code":349,"language":159,"meta":160,"style":160},"let a = [10, 20, 30];\nlet b = a;\nb.pop();\nb; \u002F\u002F As expected the output will be → [10, 20]\na; \u002F\u002F But the output of a is also → [10, 20]\n",[108,351,352,382,394,410,419],{"__ignoreMap":160},[52,353,354,356,358,360,363,366,369,372,374,377,380],{"class":165,"line":166},[52,355,170],{"class":169},[52,357,250],{"class":173},[52,359,212],{"class":177},[52,361,362],{"class":173}," [",[52,364,365],{"class":255},"10",[52,367,368],{"class":177},",",[52,370,371],{"class":255}," 20",[52,373,368],{"class":177},[52,375,376],{"class":255}," 30",[52,378,379],{"class":173},"]",[52,381,178],{"class":177},[52,383,384,386,388,390,392],{"class":165,"line":181},[52,385,170],{"class":169},[52,387,265],{"class":173},[52,389,212],{"class":177},[52,391,270],{"class":173},[52,393,178],{"class":177},[52,395,396,398,401,405,408],{"class":165,"line":275},[52,397,296],{"class":173},[52,399,400],{"class":177},".",[52,402,404],{"class":403},"s2Zo4","pop",[52,406,407],{"class":173},"()",[52,409,178],{"class":177},[52,411,412,414,416],{"class":165,"line":293},[52,413,296],{"class":173},[52,415,299],{"class":177},[52,417,418],{"class":187}," \u002F\u002F As expected the output will be → [10, 20]\n",[52,420,421,423,425],{"class":165,"line":191},[52,422,307],{"class":173},[52,424,299],{"class":177},[52,426,427],{"class":187}," \u002F\u002F But the output of a is also → [10, 20]\n",[37,429,431],{"id":430},"typeof-operator","typeof Operator",[42,433,434],{},[45,435,436],{},"Used to check the data type of a value:",[155,438,440],{"className":157,"code":439,"language":159,"meta":160,"style":160},"typeof \"Shoaib\" \u002F\u002F \"string\"\ntypeof 99 \u002F\u002F \"number\"\ntypeof true \u002F\u002F \"boolean\"\ntypeof undefined \u002F\u002F \"undefined\"\ntypeof null \u002F\u002F \"object\" ← known bug\ntypeof [] \u002F\u002F \"object\"\ntypeof {} \u002F\u002F \"object\"\ntypeof function(){} \u002F\u002F \"function\"\n",[108,441,442,460,470,481,491,501,511,522],{"__ignoreMap":160},[52,443,444,447,450,454,457],{"class":165,"line":166},[52,445,446],{"class":177},"typeof",[52,448,449],{"class":177}," \"",[52,451,453],{"class":452},"sfazB","Shoaib",[52,455,456],{"class":177},"\"",[52,458,459],{"class":187}," \u002F\u002F \"string\"\n",[52,461,462,464,467],{"class":165,"line":181},[52,463,446],{"class":177},[52,465,466],{"class":255}," 99",[52,468,469],{"class":187}," \u002F\u002F \"number\"\n",[52,471,472,474,478],{"class":165,"line":275},[52,473,446],{"class":177},[52,475,477],{"class":476},"sfNiH"," true",[52,479,480],{"class":187}," \u002F\u002F \"boolean\"\n",[52,482,483,485,488],{"class":165,"line":293},[52,484,446],{"class":177},[52,486,487],{"class":177}," undefined",[52,489,490],{"class":187}," \u002F\u002F \"undefined\"\n",[52,492,493,495,498],{"class":165,"line":191},[52,494,446],{"class":177},[52,496,497],{"class":177}," null",[52,499,500],{"class":187}," \u002F\u002F \"object\" ← known bug\n",[52,502,503,505,508],{"class":165,"line":218},[52,504,446],{"class":177},[52,506,507],{"class":173}," [] ",[52,509,510],{"class":187},"\u002F\u002F \"object\"\n",[52,512,514,516,519],{"class":165,"line":513},7,[52,515,446],{"class":177},[52,517,518],{"class":177}," {}",[52,520,521],{"class":187}," \u002F\u002F \"object\"\n",[52,523,525,527,530,533],{"class":165,"line":524},8,[52,526,446],{"class":177},[52,528,529],{"class":169}," function",[52,531,532],{"class":177},"(){}",[52,534,535],{"class":187}," \u002F\u002F \"function\"\n",[537,538,540,544,545,548],"callout",{"type":539},"info",[52,541,543],{"style":542},"color: #ef4444; font-weight: bold;","Note:"," ",[108,546,547],{},"typeof null === \"object\""," is a bug, but has existed since the early days of JS.",[37,550,552],{"id":551},"type-coercion-auto-conversion","Type Coercion (Auto-Conversion)",[42,554,555],{},[45,556,557],{},"JavaScript auto-converts types in some operations:",[155,559,561],{"className":157,"code":560,"language":159,"meta":160,"style":160},"\"5\" + 1 \u002F\u002F \"51\" → number converted to string\n\"5\" - 1 \u002F\u002F 4 → string converted to number\ntrue + 1 \u002F\u002F 2\nnull + 1 \u002F\u002F 1\nundefined + 1 \u002F\u002F NaN\n",[108,562,563,580,596,607,619],{"__ignoreMap":160},[52,564,565,567,570,572,575,577],{"class":165,"line":166},[52,566,456],{"class":177},[52,568,569],{"class":452},"5",[52,571,456],{"class":177},[52,573,574],{"class":177}," +",[52,576,288],{"class":255},[52,578,579],{"class":187}," \u002F\u002F \"51\" → number converted to string\n",[52,581,582,584,586,588,591,593],{"class":165,"line":181},[52,583,456],{"class":177},[52,585,569],{"class":452},[52,587,456],{"class":177},[52,589,590],{"class":177}," -",[52,592,288],{"class":255},[52,594,595],{"class":187}," \u002F\u002F 4 → string converted to number\n",[52,597,598,600,602,604],{"class":165,"line":275},[52,599,144],{"class":476},[52,601,574],{"class":177},[52,603,288],{"class":255},[52,605,606],{"class":187}," \u002F\u002F 2\n",[52,608,609,612,614,616],{"class":165,"line":293},[52,610,611],{"class":177},"null",[52,613,574],{"class":177},[52,615,288],{"class":255},[52,617,618],{"class":187}," \u002F\u002F 1\n",[52,620,621,624,626,628],{"class":165,"line":191},[52,622,623],{"class":177},"undefined",[52,625,574],{"class":177},[52,627,288],{"class":255},[52,629,630],{"class":187}," \u002F\u002F NaN\n",[37,632,634],{"id":633},"loose-vs-strict-equality","Loose vs Strict Equality",[42,636,637,643],{},[45,638,639,642],{},[108,640,641],{},"=="," compares value with type conversion",[45,644,645,648],{},[108,646,647],{},"==="," compares value + type (no conversion)",[155,650,652],{"className":157,"code":651,"language":159,"meta":160,"style":160},"5 == \"5\" \u002F\u002F true\n5 === \"5\" \u002F\u002F false\n",[108,653,654,670],{"__ignoreMap":160},[52,655,656,658,661,663,665,667],{"class":165,"line":166},[52,657,569],{"class":255},[52,659,660],{"class":177}," ==",[52,662,449],{"class":177},[52,664,569],{"class":452},[52,666,456],{"class":177},[52,668,669],{"class":187}," \u002F\u002F true\n",[52,671,672,674,677,679,681,683],{"class":165,"line":181},[52,673,569],{"class":255},[52,675,676],{"class":177}," ===",[52,678,449],{"class":177},[52,680,569],{"class":452},[52,682,456],{"class":177},[52,684,685],{"class":187}," \u002F\u002F false\n",[42,687,688],{},[45,689,690,691,693],{},"Always prefer ",[108,692,647],{}," for accurate comparisons.",[37,695,697],{"id":696},"nan-not-a-number","NaN – Not a Number",[155,699,701],{"className":157,"code":700,"language":159,"meta":160,"style":160},"typeof NaN \u002F\u002F \"number\"\n",[108,702,703],{"__ignoreMap":160},[52,704,705,707,710],{"class":165,"line":166},[52,706,446],{"class":177},[52,708,709],{"class":177}," NaN",[52,711,469],{"class":187},[42,713,714,723],{},[45,715,716,717,720,721,400],{},"Even though it means \"Not a Number\", ",[108,718,719],{},"NaN"," is actually of type ",[108,722,55],{},[45,724,725,726,729,730,733],{},"This is because operations like ",[108,727,728],{},"0 \u002F 0"," or ",[108,731,732],{},"parseInt(\"abc\")"," still produce a numeric result — just an invalid one.",[37,735,737],{"id":736},"truthy-and-falsy-values","Truthy and Falsy Values",[739,740,742],"h4",{"id":741},"falsy-values","Falsy values:",[68,744,745,56,747,56,750,56,753,56,755,56,757],{},[108,746,147],{},[108,748,749],{},"0",[108,751,752],{},"\"\"",[108,754,611],{},[108,756,623],{},[108,758,719],{},[68,760,761,762,765],{},"Everything else is ",[52,763,764],{"style":54},"truthy",", including:",[739,767,769],{"id":768},"truthy-values","Truthy values:",[68,771,772,56,775,56,778,56,781,56,784],{},[108,773,774],{},"\"0\"",[108,776,777],{},"\"false\"",[108,779,780],{},"[]",[108,782,783],{},"{}",[108,785,786],{},"function(){}",[155,788,790],{"className":157,"code":789,"language":159,"meta":160,"style":160},"\u002F\u002F Example:\nif (\"0\") {\n  console.log(\"Runs\"); \u002F\u002F \"0\" is a non-empty string = truthy\n}\n",[108,791,792,797,818,847],{"__ignoreMap":160},[52,793,794],{"class":165,"line":166},[52,795,796],{"class":187},"\u002F\u002F Example:\n",[52,798,799,803,806,808,810,812,815],{"class":165,"line":181},[52,800,802],{"class":801},"s7zQu","if",[52,804,805],{"class":173}," (",[52,807,456],{"class":177},[52,809,749],{"class":452},[52,811,456],{"class":177},[52,813,814],{"class":173},") ",[52,816,817],{"class":177},"{\n",[52,819,820,823,825,828,832,834,837,839,842,844],{"class":165,"line":275},[52,821,822],{"class":173},"  console",[52,824,400],{"class":177},[52,826,827],{"class":403},"log",[52,829,831],{"class":830},"swJcz","(",[52,833,456],{"class":177},[52,835,836],{"class":452},"Runs",[52,838,456],{"class":177},[52,840,841],{"class":830},")",[52,843,299],{"class":177},[52,845,846],{"class":187}," \u002F\u002F \"0\" is a non-empty string = truthy\n",[52,848,849],{"class":165,"line":293},[52,850,851],{"class":177},"}\n",[37,853,855],{"id":854},"mindset","Mindset",[42,857,858,865],{},[45,859,860,861,864],{},"JavaScript will often ",[52,862,863],{"style":54},"auto-convert types"," behind the scenes.",[45,866,867],{},"Always stay aware of what data type you're working with.",[37,869,871],{"id":870},"common-confusions","Common Confusions",[42,873,874,884,889,894],{},[45,875,876,879,880,883],{},[108,877,878],{},"typeof null"," is ",[108,881,882],{},"\"object\""," — this is a bug.",[45,885,886,888],{},[108,887,623],{}," means the variable was never assigned.",[45,890,891,893],{},[108,892,611],{}," means you intentionally set it to \"nothing\".",[45,895,896,879,899,902,903,879,906,400],{},[108,897,898],{},"'5' + 1",[108,900,901],{},"\"51\""," but ",[108,904,905],{},"'5' - 1",[108,907,908],{},"4",[37,910,912],{"id":911},"practice-zone","Practice Zone",[96,914,915],{},[45,916,917],{},"Predict the output:",[155,919,921],{"className":157,"code":920,"language":159,"meta":160,"style":160},"console.log(null + 1);\nconsole.log(\"5\" + 3);\nconsole.log(\"5\" - 3);\nconsole.log(true + false);\n",[108,922,923,944,969,993],{"__ignoreMap":160},[52,924,925,928,930,932,934,936,938,940,942],{"class":165,"line":166},[52,926,927],{"class":173},"console",[52,929,400],{"class":177},[52,931,827],{"class":403},[52,933,831],{"class":173},[52,935,611],{"class":177},[52,937,574],{"class":177},[52,939,288],{"class":255},[52,941,841],{"class":173},[52,943,178],{"class":177},[52,945,946,948,950,952,954,956,958,960,962,965,967],{"class":165,"line":181},[52,947,927],{"class":173},[52,949,400],{"class":177},[52,951,827],{"class":403},[52,953,831],{"class":173},[52,955,456],{"class":177},[52,957,569],{"class":452},[52,959,456],{"class":177},[52,961,574],{"class":177},[52,963,964],{"class":255}," 3",[52,966,841],{"class":173},[52,968,178],{"class":177},[52,970,971,973,975,977,979,981,983,985,987,989,991],{"class":165,"line":275},[52,972,927],{"class":173},[52,974,400],{"class":177},[52,976,827],{"class":403},[52,978,831],{"class":173},[52,980,456],{"class":177},[52,982,569],{"class":452},[52,984,456],{"class":177},[52,986,590],{"class":177},[52,988,964],{"class":255},[52,990,841],{"class":173},[52,992,178],{"class":177},[52,994,995,997,999,1001,1003,1005,1007,1010,1012],{"class":165,"line":293},[52,996,927],{"class":173},[52,998,400],{"class":177},[52,1000,827],{"class":403},[52,1002,831],{"class":173},[52,1004,144],{"class":476},[52,1006,574],{"class":177},[52,1008,1009],{"class":476}," false",[52,1011,841],{"class":173},[52,1013,178],{"class":177},[96,1015,1016],{"start":181},[45,1017,1018],{},"Check types:",[155,1020,1022],{"className":157,"code":1021,"language":159,"meta":160,"style":160},"console.log(typeof []);\nconsole.log(typeof null);\nconsole.log(typeof 123n);\n",[108,1023,1024,1041,1059],{"__ignoreMap":160},[52,1025,1026,1028,1030,1032,1034,1036,1039],{"class":165,"line":166},[52,1027,927],{"class":173},[52,1029,400],{"class":177},[52,1031,827],{"class":403},[52,1033,831],{"class":173},[52,1035,446],{"class":177},[52,1037,1038],{"class":173}," [])",[52,1040,178],{"class":177},[52,1042,1043,1045,1047,1049,1051,1053,1055,1057],{"class":165,"line":181},[52,1044,927],{"class":173},[52,1046,400],{"class":177},[52,1048,827],{"class":403},[52,1050,831],{"class":173},[52,1052,446],{"class":177},[52,1054,497],{"class":177},[52,1056,841],{"class":173},[52,1058,178],{"class":177},[52,1060,1061,1063,1065,1067,1069,1071,1074,1077,1079],{"class":165,"line":275},[52,1062,927],{"class":173},[52,1064,400],{"class":177},[52,1066,827],{"class":403},[52,1068,831],{"class":173},[52,1070,446],{"class":177},[52,1072,1073],{"class":255}," 123",[52,1075,1076],{"class":169},"n",[52,1078,841],{"class":173},[52,1080,178],{"class":177},[96,1082,1083],{"start":275},[45,1084,1085],{},"Truthy or Falsy?",[155,1087,1089],{"className":157,"code":1088,"language":159,"meta":160,"style":160},"console.log(Boolean(0)); \u002F\u002F falsy\nconsole.log(Boolean(\"0\")); \u002F\u002F truthy\nconsole.log(Boolean([])); \u002F\u002F truthy\nconsole.log(Boolean(undefined)); \u002F\u002F falsy\n",[108,1090,1091,1115,1142,1161],{"__ignoreMap":160},[52,1092,1093,1095,1097,1099,1101,1103,1105,1107,1110,1112],{"class":165,"line":166},[52,1094,927],{"class":173},[52,1096,400],{"class":177},[52,1098,827],{"class":403},[52,1100,831],{"class":173},[52,1102,138],{"class":403},[52,1104,831],{"class":173},[52,1106,749],{"class":255},[52,1108,1109],{"class":173},"))",[52,1111,299],{"class":177},[52,1113,1114],{"class":187}," \u002F\u002F falsy\n",[52,1116,1117,1119,1121,1123,1125,1127,1129,1131,1133,1135,1137,1139],{"class":165,"line":181},[52,1118,927],{"class":173},[52,1120,400],{"class":177},[52,1122,827],{"class":403},[52,1124,831],{"class":173},[52,1126,138],{"class":403},[52,1128,831],{"class":173},[52,1130,456],{"class":177},[52,1132,749],{"class":452},[52,1134,456],{"class":177},[52,1136,1109],{"class":173},[52,1138,299],{"class":177},[52,1140,1141],{"class":187}," \u002F\u002F truthy\n",[52,1143,1144,1146,1148,1150,1152,1154,1157,1159],{"class":165,"line":275},[52,1145,927],{"class":173},[52,1147,400],{"class":177},[52,1149,827],{"class":403},[52,1151,831],{"class":173},[52,1153,138],{"class":403},[52,1155,1156],{"class":173},"([]))",[52,1158,299],{"class":177},[52,1160,1141],{"class":187},[52,1162,1163,1165,1167,1169,1171,1173,1175,1177,1179,1181],{"class":165,"line":293},[52,1164,927],{"class":173},[52,1166,400],{"class":177},[52,1168,827],{"class":403},[52,1170,831],{"class":173},[52,1172,138],{"class":403},[52,1174,831],{"class":173},[52,1176,623],{"class":177},[52,1178,1109],{"class":173},[52,1180,299],{"class":177},[52,1182,1114],{"class":187},[96,1184,1185,1199],{"start":293},[45,1186,1187,1188,1191,1192,56,1194,1196,1197,400],{},"Write a function ",[108,1189,1190],{},"isEmpty(value)"," that checks if a given value is ",[108,1193,611],{},[108,1195,623],{},", or ",[108,1198,752],{},[45,1200,1201],{},"Compare with loose vs strict:",[155,1203,1205],{"className":157,"code":1204,"language":159,"meta":160,"style":160},"console.log(5 == \"5\"); \u002F\u002F ?\nconsole.log(5 === \"5\"); \u002F\u002F ?\n",[108,1206,1207,1234],{"__ignoreMap":160},[52,1208,1209,1211,1213,1215,1217,1219,1221,1223,1225,1227,1229,1231],{"class":165,"line":166},[52,1210,927],{"class":173},[52,1212,400],{"class":177},[52,1214,827],{"class":403},[52,1216,831],{"class":173},[52,1218,569],{"class":255},[52,1220,660],{"class":177},[52,1222,449],{"class":177},[52,1224,569],{"class":452},[52,1226,456],{"class":177},[52,1228,841],{"class":173},[52,1230,299],{"class":177},[52,1232,1233],{"class":187}," \u002F\u002F ?\n",[52,1235,1236,1238,1240,1242,1244,1246,1248,1250,1252,1254,1256,1258],{"class":165,"line":181},[52,1237,927],{"class":173},[52,1239,400],{"class":177},[52,1241,827],{"class":403},[52,1243,831],{"class":173},[52,1245,569],{"class":255},[52,1247,676],{"class":177},[52,1249,449],{"class":177},[52,1251,569],{"class":452},[52,1253,456],{"class":177},[52,1255,841],{"class":173},[52,1257,299],{"class":177},[52,1259,1233],{"class":187},[1261,1262,1263],"style",{},"html pre.shiki code .spNyl, html code.shiki .spNyl{--shiki-light:#9C3EDA;--shiki-default:#C792EA;--shiki-dark:#C792EA}html pre.shiki code .sTEyZ, html code.shiki .sTEyZ{--shiki-light:#90A4AE;--shiki-default:#EEFFFF;--shiki-dark:#BABED8}html pre.shiki code .sMK4o, html code.shiki .sMK4o{--shiki-light:#39ADB5;--shiki-default:#89DDFF;--shiki-dark:#89DDFF}html pre.shiki code .sHwdD, html code.shiki .sHwdD{--shiki-light:#90A4AE;--shiki-light-font-style:italic;--shiki-default:#546E7A;--shiki-default-font-style:italic;--shiki-dark:#676E95;--shiki-dark-font-style:italic}html .light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html.light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html .default .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}html.dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}html pre.shiki code .sbssI, html code.shiki .sbssI{--shiki-light:#F76D47;--shiki-default:#F78C6C;--shiki-dark:#F78C6C}html pre.shiki code .s2Zo4, html code.shiki .s2Zo4{--shiki-light:#6182B8;--shiki-default:#82AAFF;--shiki-dark:#82AAFF}html pre.shiki code .sfazB, html code.shiki .sfazB{--shiki-light:#91B859;--shiki-default:#C3E88D;--shiki-dark:#C3E88D}html pre.shiki code .sfNiH, html code.shiki .sfNiH{--shiki-light:#FF5370;--shiki-default:#FF9CAC;--shiki-dark:#FF9CAC}html pre.shiki code .s7zQu, html code.shiki .s7zQu{--shiki-light:#39ADB5;--shiki-light-font-style:italic;--shiki-default:#89DDFF;--shiki-default-font-style:italic;--shiki-dark:#89DDFF;--shiki-dark-font-style:italic}html pre.shiki code .swJcz, html code.shiki .swJcz{--shiki-light:#E53935;--shiki-default:#F07178;--shiki-dark:#F07178}",{"title":160,"searchDepth":181,"depth":181,"links":1265},[1266,1270,1271,1272,1273,1274,1275,1276,1277],{"id":39,"depth":181,"text":40,"children":1267},[1268,1269],{"id":93,"depth":275,"text":94},{"id":315,"depth":275,"text":316},{"id":430,"depth":181,"text":431},{"id":551,"depth":181,"text":552},{"id":633,"depth":181,"text":634},{"id":696,"depth":181,"text":697},{"id":736,"depth":181,"text":737},{"id":854,"depth":181,"text":855},{"id":870,"depth":181,"text":871},{"id":911,"depth":181,"text":912},"Learn about JavaScript data types, primitive vs reference types, typeof operator, coercion, truthy\u002Ffalsy values, and type system concepts.","md",null,{},{"title":26},{"title":1284,"description":1285},"Chapter 2: Data Types + Type System | JavaScript","Master JavaScript Data Types, Primitive vs Reference types, typeof operator, Loose vs Strict equality, and Truthy\u002FFalsy values.","GU9fdJEwch1RvQgmFXwVwczGrenxtnql_w1RcBuWVWc",[1288,1280],{"title":22,"path":23,"stem":24,"description":1289,"children":-1},"Understand variables in JavaScript, including var, let, const, block scope, function scope, and hoisting.",1786773830810]