locutus/php/var/is_numeric.js

Locutus other languages' standard libraries to JavaScript for fun and educational purposes

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.is_numeric = is_numeric;
function is_numeric(mixedVar) {
    //  discuss at: https://locutus.io/php/is_numeric/
    // original by: Kevin van Zonneveld (https://kvz.io)
    // improved by: David
    // improved by: taith
    // bugfixed by: Tim de Koning
    // bugfixed by: WebDevHobo (https://webdevhobo.blogspot.com/)
    // bugfixed by: Brett Zamir (https://brett-zamir.me)
    // bugfixed by: Denis Chenu (https://shnoulle.net)
    //   example 1: is_numeric(186.31)
    //   returns 1: true
    //   example 2: is_numeric('Kevin van Zonneveld')
    //   returns 2: false
    //   example 3: is_numeric(' +186.31e2')
    //   returns 3: true
    //   example 4: is_numeric('')
    //   returns 4: false
    //   example 5: is_numeric([])
    //   returns 5: false
    //   example 6: is_numeric('1 ')
    //   returns 6: false
    const whitespace = [
        ' ',
        '\n',
        '\r',
        '\t',
        '\f',
        '\x0b',
        '\xa0',
        '\u2000',
        '\u2001',
        '\u2002',
        '\u2003',
        '\u2004',
        '\u2005',
        '\u2006',
        '\u2007',
        '\u2008',
        '\u2009',
        '\u200a',
        '\u200b',
        '\u2028',
        '\u2029',
        '\u3000',
    ].join('');
    // @todo: Break this up using many single conditions with early returns
    if (typeof mixedVar === 'number') {
        return !Number.isNaN(mixedVar);
    }
    if (typeof mixedVar !== 'string') {
        return false;
    }
    return mixedVar !== '' && whitespace.indexOf(mixedVar.slice(-1)) === -1 && !Number.isNaN(Number(mixedVar));
}