May 14th, 2020
Finding type of data in JS
#js
JS is not a strictly typed language. So its not really easy to find out ways to say what type the input is. I will keep this post like a cheatsheet to find out all data types.
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// string
let isString = (inp) => typeof inp === "string";
// boolean
let isBoolean = (inp) => typeof inp === "boolean";
// number
let isNumber = (inp) => typeof inp === "number";
// isNumber(NaN) = true
// isNumber(Infinity) = true
// number
let isWholeNumber = (inp) => isNumber(inp) && inp % 1 === 0;
// Array
let isArray = (inp) => typeof inp === "object" && inp.constructor === Array;
// Object
let isObject = (inp) => typeof inp === "object" && inp.constructor === Object;