JavaScript:Array属性方法

var arr=[,,,,];
console.dir(arr);
var pro=Object.getPrototypeOf(arr);
console.dir(pro);

来一个个的查看数组的属性，方法

1.Array的静态方法

var arr=[,,,,];
console.log(Array.isArray(arr))  //true

2.arr的属性

var arr=[,,,,];
var con=arr.constructor;
console.dir(con);
var length=arr.length;
console.dir(length);

3.arr的方法

  1.concat

var arr=[,,,,];
var a2=arr.concat("hongda");
console.log(a2);
var a3=arr.concat(["hong","da","da"]);
console.log(a3);
var a4=arr.concat("hongda1","hongda2",["hongda3","hongda4"]);
console.log(a4);

2.every,some,map,forEach

var arr=["hong","da","da2","da3"];
//every
var result=arr.every(function(value,index,array){
  console.log("value:"+value+"       index:"+index+"          array:"+array);
  return true;
});
console.log(result);
//some
var result=arr.some(function(value,index,array){
  console.log("value:"+value+"       index:"+index+"          array:"+array);
  return true;
});
console.log(result);
//map
var result=arr.map(function(value,index,array){
  console.log("value:"+value+"       index:"+index+"          array:"+array);
  return value+index;
});
console.log(result);
//forEach
var result=arr.every(function(value,index,array){
  console.log("value:"+value+"       index:"+index+"          array:"+array);
});
console.log(result);

1，filter，按指定函数过滤元素，汇集返回值为true元素组成新的数组，函数值类型为布尔
2，forEach，在每一个元素上执行函数，函数返回类型为空
3，every，贪婪的试图匹配每一个元素，真到有一个返回false为止，函数值类型为布尔
4，some，懒惰的企图找到一个元素合乎要求，只要有一个返回true停止，函数值类型为布尔
5，map，使用同一函数处理每一个元素并返回，汇集返回结果组成新数组，函数返回类型为元素类型

3.filter

var arr = [, "element", , "the", true];
var result = arr.filter(
    function (value) {
        return (typeof value === 'string');
    }
);
console.log(result);  //element,the

5.lastIndexOf

var ar = ["ab", "cd", "ef", "ab", "cd"];
console.log(ar.lastIndexOf("cd"));  //4

6.reduce

var arr=["hong","da","da2","da3"];
var result=arr.reduce(function(previousValue,currentValue,currentIndex,array){
 console.log("previousValue:"+previousValue+"          currentValue:"+currentValue+"       currentIndex:"+currentIndex+"          array:"+array);
});

var arr=["hong","da","da2","da3"];
var result=arr.reduce(function(previousValue,currentValue,currentIndex,array){
 console.log("previousValue:"+previousValue+"          currentValue:"+currentValue+"       currentIndex:"+currentIndex+"          array:"+array);
 return currentValue+currentIndex;
});
console.log(result);

var arr=["hong","da","da2","da3"];
var result=arr.reduce(function(previousValue,currentValue,currentIndex,array){
 console.log("previousValue:"+previousValue+"          currentValue:"+currentValue+"       currentIndex:"+currentIndex+"          array:"+array);
 return previousValue+currentValue;
});
console.log(result);

7.reduceRight

var arr=["hong","da","da2","da3"];
var result=arr.reduceRight(function(previousValue,currentValue,currentIndex,array){
 console.log("previousValue:"+previousValue+"          currentValue:"+currentValue+"       currentIndex:"+currentIndex+"          array:"+array);
 return previousValue+currentValue;
});

8.reverse

var arr=["hong","da","da2","da3"];
var result=arr.reverse();
console.log(result);
console.log(arr);

9.sort

var a = new Array(, , , , , );

var b = a.sort();
document.write(b);
document.write("<br/>");

// This is ASCII character order.
// Output: 1,10,11,2,3,4)

// Sort the array elements with a function that compares array elements.
b = a.sort(CompareForSort);
document.write(b);
document.write("<br/>");
// Output: 1,2,3,4,10,11.

// Sorts array elements in ascending order numerically.
function CompareForSort(first, second)
{
    if (first == second)
        return ;
    if (first < second)
        return -;
    else
        return ;
}

http://msdn.microsoft.com/zh-tw/library/k4h76zbx(v=vs.94).aspx