Summary of JS functions commonly used in front-end development (1)

function isStatic(value) {
	return (
		typeof value === 'string' ||
		typeof value === 'number' ||
		typeof value === 'boolean' ||
		typeof value === 'undefined' ||
		value === null
	)
}

function isPrimitive(value) {
	return isStatic(value) || typeof value === 'symbol'
}

function isObject(value) {
	let type = typeof value;
	return value != null && (type == 'object' || type == 'function');
}

function isObjectLike(value) {
	return value != null && typeof value == 'object';
}

function getRawType(value) {
	return Object.prototype.toString.call(value).slice(8, -1)
}
// getoRawType([]) ⇒ Array

function isPlainObject(obj) {
	return Object.prototype.toString.call(obj) === '[object Object]'
}

function isArray(arr) {
	return Object.prototype.toString.call(arr) === '[object Array]'
}

// 将isArray挂载到Array上
Array.isArray = Array.isArray || isArray;

function isRegExp(value) {
	return Object.prototype.toString.call(value) === '[object RegExp]'
}

function isDate(value) {
    return Object.prototype.toString.call(value) === '[object Date]'
}

function isNative(value) {
	return typeof value === 'function' && /native code/.test(value.toString())
}

function isFunction(value) {
	return Object.prototype.toString.call(value) === '[object Function]'
}

function isLength(value) {
	return typeof value == &#39;number&#39; && value > -1 && value % 1 == 0 && value <= Number.MAX_SAFE_INTEGER;
}

function isArrayLike(value) {
	return value != null && isLength(value.length) && !isFunction(value);
}

function isEmpty(value) {
	if (value == null) {
		return true;
	}
	if (isArrayLike(value)) {
		return !value.length;
	} else if (isPlainObject(value)) {
		for (let key in value) {
			if (hasOwnProperty.call(value, key)) {
				return false;
			}
		}
	}
	return false;
}

function cached(fn) {
	let cache = Object.create(null);
	return function cachedFn(str) {
		let hit = cache[str];
		return hit || (cache[str] = fn(str))
	}
}

let camelizeRE = /-(\w)/g;
function camelize(str) {
	return str.replace(camelizeRE, function(_, c) {
		return c ? c.toUpperCase() : '';
	})
}
//ab-cd-ef ==> abCdEf
//使用记忆函数
let _camelize = cached(camelize)

let hyphenateRE = /\B([A-Z])/g;
function hyphenate(str){
    return str.replace(hyphenateRE, '-$1').toLowerCase()
}
//abCd ==> ab-cd
//使用记忆函数
let _hyphenate = cached(hyphenate);

function capitalize(str) {
	return str.charAt(0).toUpperCase() + str.slice(1)
}
// abc ==> Abc
//使用记忆函数
let _capitalize = cached(capitalize)

function extend(to, _form) {
	for(let key in _form) {
		to[key] = _form[key];
	}
	return to
}

Object.assign = Object.assign || function() {
	if (arguments.length == 0) throw new TypeError('Cannot convert undefined or null to object');
	let target = arguments[0],
		args = Array.prototype.slice.call(arguments, 1),
		key;
	args.forEach(function(item) {
		for (key in item) {
			item.hasOwnProperty(key) && (target[key] = item[key])
		}
	})
	return target
}

let clone = Object.assign({}, target);

let clone = JSON.parse( JSON.stringify(target) )

function clone(value, deep) {
	if (isPrimitive(value)) {
		return value
	}
	if (isArrayLike(value)) {  //是类数组
		value = Array.prototype.slice.call(vall)
		return value.map(item => deep ? clone(item, deep) : item)
	} else if (isPlainObject(value)) {  //是对象
		let target = {}, key;
		for (key in value) {
			value.hasOwnProperty(key) && ( target[key] = deep ? clone(value[key], value[key] ))
		}
	}
	let type = getRawType(value);
	switch(type) {
		case 'Date':
		case 'RegExp':
		case 'Error': value = new window[type](value); break;
	}
	return value
}

//运行环境是浏览器
let inBrowser = typeof window !== 'undefined';
//运行环境是微信
let inWeex = typeof WXEnvironment !== 'undefined' && !!WXEnvironment.platform;
let weexPlatform = inWeex && WXEnvironment.platform.toLowerCase();
//浏览器 UA 判断
let UA = inBrowser && window.navigator.userAgent.toLowerCase();
let isIE = UA && /msie|trident/.test(UA);
let isIE9 = UA && UA.indexOf('msie 9.0') > 0;
let isEdge = UA && UA.indexOf('edge/') > 0;
let isAndroid = (UA && UA.indexOf('android') > 0) || (weexPlatform === 'android');
let isIOS = (UA && /iphone|ipad|ipod|ios/.test(UA)) || (weexPlatform === 'ios');
let isChrome = UA && /chrome\/\d+/.test(UA) && !isEdge;

function getExplorerInfo() {
    let t = navigator.userAgent.toLowerCase();
    return 0 <= t.indexOf("msie") ? { //ie < 11
        type: "IE",
        version: Number(t.match(/msie ([\d]+)/)[1])
    } : !!t.match(/trident\/.+?rv:(([\d.]+))/) ? { // ie 11
        type: "IE",
        version: 11
    } : 0 <= t.indexOf("edge") ? {
        type: "Edge",
        version: Number(t.match(/edge\/([\d]+)/)[1])
    } : 0 <= t.indexOf("firefox") ? {
        type: "Firefox",
        version: Number(t.match(/firefox\/([\d]+)/)[1])
    } : 0 <= t.indexOf("chrome") ? {
        type: "Chrome",
        version: Number(t.match(/chrome\/([\d]+)/)[1])
    } : 0 <= t.indexOf("opera") ? {
        type: "Opera",
        version: Number(t.match(/opera.([\d]+)/)[1])
    } : 0 <= t.indexOf("Safari") ? {
        type: "Safari",
        version: Number(t.match(/version\/([\d]+)/)[1])
    } : {
        type: t,
        version: -1
    }
}

function isPCBroswer() {
    let e = navigator.userAgent.toLowerCase()
        , t = "ipad" == e.match(/ipad/i)
        , i = "iphone" == e.match(/iphone/i)
        , r = "midp" == e.match(/midp/i)
        , n = "rv:1.2.3.4" == e.match(/rv:1.2.3.4/i)
        , a = "ucweb" == e.match(/ucweb/i)
        , o = "android" == e.match(/android/i)
        , s = "windows ce" == e.match(/windows ce/i)
        , l = "windows mobile" == e.match(/windows mobile/i);
    return !(t || i || r || n || a || o || s || l)
}