guy
7 years ago
3 changed files with 267 additions and 69 deletions
@ -1,31 +1,97 @@
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if(![].indexOf){ |
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/** |
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* 检查指定的值是否在数组中 |
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* @param {Object} o 要检查的值 |
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* @return {Number} o在数组中的索引（如果不在数组中则返回-1） |
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*/ |
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Array.prototype.indexOf = function (o) { |
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for (var i = 0, len = this.length; i < len; i++) { |
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if (_.isEqual(o, this[i])) { |
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return i; |
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// Production steps of ECMA-262, Edition 5, 15.4.4.14
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// Reference: http://es5.github.io/#x15.4.4.14
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if (!Array.prototype.indexOf) { |
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Array.prototype.indexOf = function (searchElement, fromIndex) { |
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var k; |
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// 1. Let o be the result of calling ToObject passing
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// the this value as the argument.
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if (this == null) { |
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throw new TypeError('"this" is null or not defined'); |
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} |
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var o = Object(this); |
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// 2. Let lenValue be the result of calling the Get
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// internal method of o with the argument "length".
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// 3. Let len be ToUint32(lenValue).
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var len = o.length >>> 0; |
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// 4. If len is 0, return -1.
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if (len === 0) { |
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return -1; |
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} |
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// 5. If argument fromIndex was passed let n be
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// ToInteger(fromIndex); else let n be 0.
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var n = fromIndex | 0; |
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// 6. If n >= len, return -1.
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if (n >= len) { |
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return -1; |
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} |
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// 7. If n >= 0, then Let k be n.
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// 8. Else, n<0, Let k be len - abs(n).
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// If k is less than 0, then let k be 0.
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k = Math.max(n >= 0 ? n : len - Math.abs(n), 0); |
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// 9. Repeat, while k < len
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while (k < len) { |
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// a. Let Pk be ToString(k).
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// This is implicit for LHS operands of the in operator
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// b. Let kPresent be the result of calling the
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// HasProperty internal method of o with argument Pk.
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// This step can be combined with c
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// c. If kPresent is true, then
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// i. Let elementK be the result of calling the Get
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// internal method of o with the argument ToString(k).
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// ii. Let same be the result of applying the
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// Strict Equality Comparison Algorithm to
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// searchElement and elementK.
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// iii. If same is true, return k.
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if (k in o && o[k] === searchElement) { |
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return k; |
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} |
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k++; |
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} |
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return -1; |
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} |
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}; |
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} |
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if(![].lastIndexOf){ |
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/** |
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* 检查指定的值是否在数组中 |
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* ie67不支持数组的这个方法 |
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* @param {Object} o 要检查的值 |
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* @return {Number} o在数组中的索引（如果不在数组中则返回-1） |
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*/ |
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Array.prototype.lastIndexOf = function (o) { |
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for (var len = this.length, i = len - 1; i >= 0; i--) { |
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if (_.isEqual(o, this[i])) { |
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return i; |
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if (!Array.prototype.lastIndexOf) { |
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Array.prototype.lastIndexOf = function (searchElement /*, fromIndex*/) { |
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'use strict'; |
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if (this === void 0 || this === null) { |
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throw new TypeError(); |
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} |
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var n, k, |
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t = Object(this), |
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len = t.length >>> 0; |
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if (len === 0) { |
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return -1; |
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} |
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n = len - 1; |
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if (arguments.length > 1) { |
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n = Number(arguments[1]); |
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if (n != n) { |
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n = 0; |
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} |
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else if (n != 0 && n != (1 / 0) && n != -(1 / 0)) { |
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n = (n > 0 || -1) * Math.floor(Math.abs(n)); |
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} |
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} |
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for (k = n >= 0 |
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? Math.min(n, len - 1) |
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: len - Math.abs(n); k >= 0; k--) { |
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if (k in t && t[k] === searchElement) { |
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return k; |
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} |
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} |
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return -1; |
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} |
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}; |
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} |
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