72 lines
1.3 KiB
JavaScript
72 lines
1.3 KiB
JavaScript
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/**
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* @author yutent<yutent.io@gmail.com>
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* @date 2020/09/16 11:54:31
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*/
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// 判断数组是否包含指定元素
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if (!Array.prototype.includes) {
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Object.defineProperty(Array.prototype, 'includes', {
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value: function(val) {
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for (let it of this) {
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if (it === val) {
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return true
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}
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}
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return false
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},
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enumerable: false,
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writable: true
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})
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}
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if (!Array.prototype.flat) {
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Object.defineProperty(Array.prototype, 'flat', {
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value: function(deep = 1) {
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var arr = []
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if (deep < 0) {
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deep = 0
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}
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deep--
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for (let it of this) {
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if (it === void 0) {
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continue
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}
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if (Array.isArray(it) && deep >= 0) {
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arr = arr.concat(it.flat(deep))
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} else {
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arr.push(it)
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}
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}
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return arr
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},
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enumerable: false,
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writable: true
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})
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// 没有flat, 当然也不会flatMap
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Object.defineProperty(Array.prototype, 'flatMap', {
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value: function(fn) {
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return this.map(fn).flat()
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},
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enumerable: false,
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writable: true
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})
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}
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if (!Array.prototype.item) {
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Object.defineProperty(Array.prototype, 'item', {
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value: function(num) {
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var n = +num
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if (n < 0) {
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n = this.length + n
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}
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return this[n]
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},
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enumerable: false,
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writable: true
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})
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}
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