Return value = null ? '' : (typeof value = 'object' & !value. If you don't like strings like 'Hello, undefined' or want to support prototype-less objects, use the following type conversion function: /** You can use the + (plus) operator to do this. Note: String(x) will still fail on prototype-less objects like Object.create(null). There exists a short hand in JavaScript for converting string values to numbers. X.toString() throws on nulls and undefined. JavaScript numbers are always stored as double precision floating point numbers, following the international IEEE 754 standard. For strings, Number () returns a number or NaN. For dates, Number () returns milliseconds since Janu00:00:00. Notes For booleans, Number () returns 0 or 1. If the value cannot be converted, NaN is returned. valueOf() on x (casting to number), throws on Symbols, can provide implementation dependent results. Valid e-notation numbers in Javascript: 123e1 > 1230 123E1 > 1230 123e+1 > 1230 123.e+1 > 1230 (with missing fractional part) 123e-1 > 12.3 0.1e-1 > 0.01. Definition and Usage The Number () method converts a value to a number. String(x) handles nulls, undefined, Symbols, and calls. Ways to Convert a String into a Number Using Number() Using parseInt() Using parseFloat() Using Unary Operator (+) Using Math.floor() Using Double tilde (. Do not use 3 ways for simple operation, basing on value type assumptions, like "here I convert definitely number to string and here definitely boolean to string". The only valid solution for almost all possible existing and future cases (input is number, null, undefined, Symbol, anything else) is String(x).
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