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JavaScript - data types
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In this article, we'll show you commonly used data types in JavaScript.
There are eight basic data types:
stringfor strings (zero or more characters).numberfor integers or floating points.bigintis for integer numbers of arbitrary length.boolean- only havetrue/falsevalue.nullfor unknown values.undefinedfor unassigned values.object- key-value pairs of collection of data.symbolfor unique identifiers.
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console.log( typeof('sample text') ); // string2
console.log( typeof( 0 ) ); // number3
console.log( typeof( 10n ) ); // bigint4
console.log( typeof( true ) ); // boolean5
console.log( typeof( null ) ); // object6
console.log( typeof( undefined ) ); // undefined7
console.log( typeof( Symbol('example_id'))); // symbol8
console.log( typeof( Math ) ); // object9
console.log( typeof( Date ) ); // functionxxxxxxxxxx1
function Student() {2
// class logic...3
}4
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console.log(typeof( null )); // object6
console.log(typeof( undefined )); // -----> undefined7
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console.log(typeof( { } )); // object9
console.log(typeof( new Object() )); // object10
console.log(typeof( new Student() )); // object11
console.log(typeof( new function() { } )); // object12
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console.log(typeof( [ ] )); // object14
console.log(typeof( new Array() )); // object15
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console.log(typeof( true )); // -----> boolean17
console.log(typeof( Boolean(true) )); // -----> boolean18
console.log(typeof( new Boolean(true) )); // object19
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console.log(typeof( 5 )); // -----> number21
console.log(typeof( Number(5) )); // -----> number22
console.log(typeof( new Number(5) )); // object23
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console.log(typeof( 5n )); // -----> bigint25
console.log(typeof( BigInt(5) )); // -----> bigint26
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console.log(typeof( 'a' )); // -----> string28
console.log(typeof( String('a') )); // -----> string29
console.log(typeof( new String('a') )); // object30
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console.log(typeof( function() { } )); // function32
console.log(typeof( Date )); // function33
console.log(typeof( RegExp )); // function34
console.log(typeof( Function )); // function35
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console.log(typeof( new Function('') )); // function37
console.log(typeof( new Date() )); // object38
console.log(typeof( /[a-z]/g )); // object39
console.log(typeof( new RegExp('[a-z]', 'g') )); // objectNote: simple types and
undefinedwere marked in comments with----->.
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ENTRY typeof toString instanceof2
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null object Null false (for Object)4
undefined undefined Undefined false (for Object)5
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{ } object Object true (for Object)7
new Object() object Object true (for Object)8
new Student() object Object true (for Student) // custom class used9
new function() { } object Object true (for Object)10
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[ ] object Array true (for Array)12
new Array() object Array true (for Array)13
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true boolean Boolean false (for Boolean) 15
Boolean(true) boolean Boolean false (for Boolean)16
new Boolean(true) object Boolean true (for Boolean)17
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5 number Number false (for Number)19
Number(5) number Number false (for Number)20
new Number(5) object Number true (for Number)21
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5n bigint BigInt false (for BigInt)23
BigInt(5) bigint BigInt false (for BigInt)24
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'a' string String false (for String)26
String('a') string String false (for String)27
new String('a') object String true (for String)28
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function() { } function Function true (for Function)30
Date function Function true (for Function)31
RegExp function Function true (for Function)32
Function function Function true (for Function)33
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new Function('') function Function true (for Function)35
new Date() object Date true (for Date)36
/[a-z]/g object RegExp true (for RegExp)37
new RegExp('[a-z]', 'g') object RegExp true (for RegExp) 