dojo 对Javascript1.6 的数组操作功能进行了拓展:
- clearCache()
- every(arr,callback,thisObject) Determines whether or not every item in arr satisfies the condition implemented by callback.
- filter(arr,thisObject) Returns a new Array with those items from arr that match the condition implemented by callback.
- forEach(arr,thisObject) for every item in arr,callback is invoked.
- indexOf(arr,value,fromIndex,findLast) locates the first index of the provided value in the passed array.
- lastIndexOf(arr,fromIndex) locates the last index of the provided value in the passed array.
- map(arr,thisObject,Ctr) applies callback to each element of arr and returns an Array with the results
- some(arr,thisObject) Determines whether or not any item in arr satisfies the condition implemented by callback.
1.every(arr,thisObject); 校验是否数组arr内的所有元素都满足回调函数的条件,是返回true
Parameter |
Type |
Description |
arr |
Array | String |
用来迭代的数组. 如果是string,则对string的没资格字符操作 |
callback |
Function | String |
回调函数被触发,三个参数: item,index,and array ,如果条件满足,返回为true |
thisObject |
Object |
可选 可能作为回调函数的作用域 |
- // returns false
- array.every([1,2,3,4],function(item){ return item>1; });
- // returns true
- array.every([1,function(item){ return item>0; });
2.filter(arr,thisObject) ; 返回一个满足过滤条件元素组成的数组
Parameter |
Type |
Description |
arr |
Array |
the array to iterate over. |
callback |
Function | String |
a function that is invoked with three arguments (item,array). The return of this function is expected to be a boolean which determines whether the passed-in item will be included in the returned array. |
thisObject |
Object |
Optional may be used to scope the call to callback |
- // Example
- // returns [2,4]
- array.filter([1,function(item){ return item>1; });
3.forEach(arr,thisObject) 对arr 的每一个元素,触发回调函数
- // log out all members of the array:
- array.forEach(
- [ "thinger","blah","howdy",10 ],function(item){
- console.log(item);
- }
- );
- // log out the members and their indexes
- array.forEach(
- [ "thinger",function(item,idx,arr){
- console.log(item,"at index:",idx);
- }
- );
- // use a scoped object member as the callback
- var obj = {
- prefix: "logged via obj.callback:",callback: function(item){
- console.log(this.prefix,item);
- }
- };
- // specifying the scope function executes the callback in that scope
- array.forEach(
- [ "thinger",obj.callback,obj
- );
- // alternately,we can accomplish the same thing with lang.hitch()
- array.forEach(
- [ "thinger",lang.hitch(obj,"callback")
- );
4.indexOf(arr,findLast) 从fromIndex 起,返回arr数组中第一次出现value的索引值.
Parameter |
Type |
Description |
arr |
Array |
|
value |
Object |
|
fromIndex |
Integer |
Optional |
findLast |
Boolean |
Optional Makes indexOf() work like lastIndexOf(). Used internally; not meant for external usage. |
Parameter |
Type |
Description |
arr |
Array | String |
the array to iterate on. If a string,operates on individual characters. |
callback |
Function | String |
a function is invoked with three arguments,(item,array),and returns a value |
thisObject |
Object |
Optional may be used to scope the call to callback |
Ctr |
undefined |
- // returns [2,4,5]
- array.map([1,function(item){ return item+1 });
6.some(arr,thisObject) 检验数组里是否有满足回调函数条件,有则返回true
Parameter |
Type |
Description |
arr |
Array | String |
the array to iterate over. If a string,operates on individual characters. |
callback |
Function | String |
a function is invoked with three arguments: item,and array and returns true if the condition is met. |
thisObject |
Object |
Optional may be used to scope the call to callback |
- // is true
- array.some([1,function(item){ return item>1; });
- // is false
- array.some([1,function(item){ return item<1; });