locomotive-boilerplate/assets/scripts/utils/is.js

var toString = Object.prototype.toString,
    arrayLikePattern = /^\[object (?:Array|FileList)\]$/;

// thanks, http://perfectionkills.com/instanceof-considered-harmful-or-how-to-write-a-robust-isarray/
export function isArray ( thing ) {
    return toString.call( thing ) === '[object Array]';
}

export function isArrayLike ( obj ) {
    return arrayLikePattern.test( toString.call( obj ) );
}

export function isEqual ( a, b ) {
    if ( a === null && b === null ) {
        return true;
    }

    if ( typeof a === 'object' || typeof b === 'object' ) {
        return false;
    }

    return a === b;
}

// http://stackoverflow.com/questions/18082/validate-numbers-in-javascript-isnumeric
export function isNumeric ( thing ) {
    return !isNaN( parseFloat( thing ) ) && isFinite( thing );
}

export function isObject ( thing ) {
    return ( thing && toString.call( thing ) === '[object Object]' );
}

export function isFunction( thing ) {
    var getType = {};
    return thing && getType.toString.call(thing) === '[object Function]';
}