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June 25, 2020 13:06
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Generic type-checking
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// from https://blog.logrocket.com/javascript-typeof-2511d53a1a62 | |
function getType(value) { | |
var regex = /^\[object (\S+?)\]$/; | |
var matches = Object.prototype.toString.call(value).match(regex) || []; | |
return (matches[1] || 'undefined').toLowerCase(); | |
} | |
console.log(type('')); // "string" | |
console.log(type('hello')); // "string" | |
console.log(type(String('hello'))); // "string" | |
console.log(type(new String('hello'))); // "string" | |
console.log(type(0)); // "number" | |
console.log(type(-0)); // "number" | |
console.log(type(0xff)); // "number" | |
console.log(type(-3.142)); // "number" | |
console.log(type(Infinity)); // "number" | |
console.log(type(-Infinity)); // "number" | |
console.log(type(NaN)); // "number" | |
console.log(type(Number(53))); // "number" | |
console.log(type(new Number(53))); // "number" | |
console.log(type(true)); // "boolean" | |
console.log(type(false)); // "boolean" | |
console.log(type(new Boolean(true))); // "boolean" | |
console.log(type(undefined)); // "undefined" | |
console.log(type(null)); // "null" | |
console.log(type(Symbol())); // "symbol" | |
console.log(type(Symbol.species)); // "symbol" | |
console.log(type([])); // "array" | |
console.log(type(Array(5))); // "array" | |
console.log((function() { return type(arguments) })()); // "arguments" | |
console.log(type(function() {})); // "function" | |
console.log(type(new Function)); // "function" | |
console.log(type(class {})); // "function" | |
console.log(type({})); // "object" | |
console.log(type(new Object)); // "object" | |
console.log(type(/^(.+)$/)); // "regexp" | |
console.log(type(new RegExp("^(.+)$"))); // "regexp" | |
console.log(type(new Date)); // "date" | |
console.log(type(new Set)); // "set" | |
console.log(type(new Map)); // "map" | |
console.log(type(new WeakSet)); // "weakset" | |
console.log(type(new WeakMap)); // "weakmap" |
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