Array ie兼容性

https://blog.csdn.net/poptxz/article/details/73836028

if (typeof Array.prototype.forEach != "function") {
Array.prototype.forEach = function (fn, context) {
for (var k = 0, length = this.length; k < length; k++) {
if (typeof fn === "function" && Object.prototype.hasOwnProperty.call(this, k)) fn.call(context, this[k], k, this);
}
};
}

if (typeof Array.prototype.map != "function") {
Array.prototype.map = function (fn, context) {
var arr = [];
if (typeof fn === "function") {
for (var k = 0, length = this.length; k < length; k++) {
arr.push(fn.call(context, this[k], k, this));
}
}
return arr;
};
}

if (typeof Array.prototype.filter != "function") {
Array.prototype.filter = function (fn, context) {
var arr = [];
if (typeof fn === "function") {
for (var k = 0, length = this.length; k < length; k++) {
fn.call(context, this[k], k, this) && arr.push(this[k]);
}
}
return arr;
};
}

if (typeof Array.prototype.some != "function") {
Array.prototype.some = function (fn, context) {
var passed = false;
if (typeof fn === "function") {
for (var k = 0, length = this.length; k < length; k++) {
if (passed === true) break;
passed = !!fn.call(context, this[k], k, this);
}
}
return passed;
};
}

if (typeof Array.prototype.every != "function") {
Array.prototype.every = function (fn, context) {
var passed = true;
if (typeof fn === "function") {
for (var k = 0, length = this.length; k < length; k++) {
if (passed === false) break;
passed = !!fn.call(context, this[k], k, this);
}
}
return passed;
};
}

if (typeof Array.prototype.indexOf != "function") {
Array.prototype.indexOf = function (searchElement, fromIndex) {
var index = -1;
fromIndex = fromIndex * 1 || 0;

for (var k = 0, length = this.length; k < length; k++) {
  if (k >= fromIndex && this[k] === searchElement) {
      index = k;
      break;
  }
}
return index;

};
}

if (typeof Array.prototype.lastIndexOf != "function") {
Array.prototype.lastIndexOf = function (searchElement, fromIndex) {
var index = -1, length = this.length;
fromIndex = fromIndex * 1 || length - 1;

for (var k = length - 1; k > -1; k-=1) {
    if (k <= fromIndex && this[k] === searchElement) {
        index = k;
        break;
    }
}
return index;

};
}

if (typeof Array.prototype.reduce != "function") {
Array.prototype.reduce = function (callback, initialValue ) {
var previous = initialValue, k = 0, length = this.length;
if (typeof initialValue === "undefined") {
previous = this[0];
k = 1;
}

if (typeof callback === "function") {
  for (k; k < length; k++) {
     this.hasOwnProperty(k) && (previous = callback(previous, this[k], k, this));
  }
}
return previous;

};
}

if (typeof Array.prototype.reduceRight != "function") {
Array.prototype.reduceRight = function (callback, initialValue ) {
var length = this.length, k = length - 1, previous = initialValue;
if (typeof initialValue === "undefined") {
previous = this[length - 1];
k--;
}
if (typeof callback === "function") {
for (k; k > -1; k-=1) {
this.hasOwnProperty(k) && (previous = callback(previous, this[k], k, this));
}
}
return previous;
};
}