js-常用数组方法总结

时间：2022-08-11 19:15:20

【前面的话】说数组“万能”，可能夸张了一点，但是就个人观点，数组的运用是非常广泛的，这里的广泛当然也包含了在其他语言中的运用。举例说明，在javascript当中，由于字符串的不可变性，在进行字符串拼接等操作中，都极大的消耗了内存，这时候用数组来“装载”字符串，操作简单，又不消耗过多的内存，真可谓是“香饽饽”。下面我总结了数组当中常用的一些操作。

——首先我们来对数组进行简单的介绍：

js-常用数组方法总结
//   var o = { };

//   o.c     属性；

//   o["c"]   键-值 的集合； 字典

// 这两个的效果是一样的

var array = [6,7,5,84,6];

//所有对象，都具有toString和valueOf

console.log(array.toString());//toSTring内部就调用join()

console.log(array.valueOf());//返回当前数组对象
js-常用数组方法总结

 1、 array.join();    // 将数组元素连接起来以构建一个字符串

1 // 将一个字符串数组输出为|分割的形式，比如“刘备|张飞|关羽”。使用两种方式实现

2  var array = ["刘备","张飞","关羽"];

3  console.log(array.join("|"));

2、 array.reverse();    // 颠倒数组中元素的顺序

1 //    将一个字符串数组的元素的顺序进行反转。["a","b","c","d]——>["d","c","b","a"]

2       var array = ["a","b","c","d"];

3       array.reverse();

4       console.log(array);

3、 array.filter();    // 使用指定的函数测试所有元素，并创建一个包含所有通过测试的元素的新数组    //这里涉及到兼容旧环境的问题

js-常用数组方法总结
 1 var array = [1500,1200,2000,2100,1800];

 2        //会把筛选的结果返回一个新数组

 3  array = array.filter(function(element,index,thisObj){

 4        //element 数组中的每一个元素

 5        //index 索引

 6        //thisObj 当前数组对象

 7     if (element >= 2000) {

 8          return false;

 9     }

10     return true;

11  });

12     console.log(array);
js-常用数组方法总结
4、 array.indexOf();
            array.lastIndexOf();
js-常用数组方法总结
//    ["c","a","z","a","x","a"]找到数组中每一个a出现的位置,找不到返回-1

        //indexOf  获取数组中第一个符合条件元素的位置

        //lastIndexOf   获取数组中最后一个符合条件的元素的位置     

      var array = ["a","a","z","a","x","a"];

      console.log(array.indexOf("a",2));

      console.log(array.lastIndexOf("a"));

//

      var index = -1;

      do {

           index = array.indexOf("a", index+1);

           if (index != -1) {

           console.log(index);

          }

       }while(index != -1);
js-常用数组方法总结

5、 array.sort();

js-常用数组方法总结
 1 //    ["c","a","z","a","x","a"]编写一个方法，求数组中每一个字符出现的次数

 2 //    排序

 3      var array = [3,6,1,5,10,2];

 4 //   array.sort();//如果不传参数，按默认的方式排序，按第一个字符的ascii码排序

 5 //   console.log(array);

 6

 7 //如果 compareFunction(a, b) 小于 0 ，那么 a 会被排列到 b 之前；

 8 //如果 compareFunction(a, b) 等于 0 ， a 和 b 的相对位置不变。备注： ECMAScript 标准并不保证这一行为，而且也不是所有浏览器都会遵守（例如 Mozilla 在 2003 年之前的版本）；

 9 //如果 compareFunction(a, b) 大于 0 ， b 会被排列到 a 之前。

10     array.sort(function(a,b) {

11         return a - b;

12     });

13     console.log(array);

14

15 //调用自己模拟的sort

16 //sort(array, function(a,b) {

17 //    return -(a - b);

18 //});

19 //console.log(array);
js-常用数组方法总结

6、 array.splice();  //插入、删除或替换数组的元素

var a = [1,2,3,4,5,6,7,8]

a.splice(4);        // 返回 [5,6,7,8]; a is [1,2,3,4]

a.splice(1,2);      // 返回 [2,3]; a is [1,4]

a.splice(1,1);      // Netscape/JavaScript 1.2 返回 4 ，应该返回 [4]

a.splice(1,0,2,3);  // Netscape/JavaScript 1.2 返回 undefined ，应该返回 []

7、 array.slice();  // 从当前数组截取一个新数组

var a = [1,2,3,4,5];

a.slice(0,3);    // 返回 [1,2,3]

a.slice(3);      // 返回 [4,5]

a.slice(1,-1);   // 返回 [2,3,4]

a.slice(-3,-2);  // 返回 [3]; IE 4存在的Bug: 返回[1,2,3]
8、 array.forEach();   //遍历数组 
                                    //  注意与filter的区别
                                    //这里涉及到兼容旧环境
js-常用数组方法总结
 1     var array = [4,6,7,8,3,46,8];

 2

 3         //forEach  遍历数组

 4 //        array.filter(function (item,index,obj) {

 5 //        })

 6

 7         for(var i = 0; i < array.length ; i++) {

 8             var item = array[i];

 9         }

10

11         array.forEach(function (item, index,obj) {

12             console.log(item);

13             console.log(index);

14             console.log(obj);

15         })
js-常用数组方法总结

【输出】

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" alt="" />

9、 html5提供的方法：
i）indexOf ；    lastIndexOf
ii）filter ；  forEach   

10、清空数组的三种方式：

js-常用数组方法总结
var array = [1, 2, 3, 4];

//方式1

array.splice(0,array.length); //删除数组中所有项

//方式2

array.length = 0;  //length属性可以赋值，length是只读

//方式3

array = [];  // 推荐
js-常用数组方法总结

js中数组Array的一些常用方法总结

var list = new Array()是我们在js中常常写到的代码，今天就总结一下Array的对象具有哪些方法。

　　list[0] = 0;

　　list[1] = 1;

　　list[2] = 2;

　　或者这样声明：var list = [0,1,2];

(1) shift():

　　 alert(list.shift());　　 //删除数组的第一个元素,返回删除的值。这里是0 
　　 alert(list.length);　　//返回的数组长度是2

(2) unshift( i , j ):

list.unshift(3,4);　　//把参数加载数组的前面,现在list:中是3,4,0,1,2

　　 alert(list.length);　　//现在数组的长度是5

(3) pop():

list.pop();　　 //删除数组的最后一个元素,返回删除的值。这里是2
　  alert(list.length);　　//返回的数组长度是2

(4)push(param):

list.push(3);　　//将参数加载到数组的最后，现在List中是：0,1,2,3

alert(list.length);　　　//返回的数组长度是4

(5)concat( i , j ):

alert(list.concat(5,6));  //将参数与之前的数组list拼接起来，现在的list是：0,1,2,5,6

alert(list.length);        //返回的数组长度是5

(6) splice(start,deleteCount,val1,val2,...)：从start位置开始删除deleteCount项，并从该位置起插入val1,val2,...

(7) reverse：将数组反序 
  var a = [1,2,3,4,5]; 
  var b = a.reverse(); //a：[5,4,3,2,1] b：[5,4,3,2,1]

(8) sort(orderfunction)：按指定的参数对数组进行排序 
  var a = [1,2,3,4,5]; 
  var b = a.sort(); //a：[1,2,3,4,5] b：[1,2,3,4,5]

(9) slice(start,end)：返回从原数组中指定开始下标到结束下标之间的项组成的新数组 
  var a = [1,2,3,4,5]; 
  var b = a.slice(2,5); //a：[1,2,3,4,5] b：[3,4,5]

(10) join(separator)：将数组的元素组起一个字符串，以separator为分隔符，省略的话则用默认用逗号为分隔符 
  var a = [1,2,3,4,5]; 
  var b = a.join("|"); //a：[1,2,3,4,5] b："1|2|3|4|5"

-----转

//shift：删除原数组第一项，并返回删除元素的值；如果数组为空则返回undefined

var a = [1,2,3,4,5];

var b = a.shift(); //a：[2,3,4,5] b：1

//unshift：将参数添加到原数组开头，并返回数组的长度

var a = [1,2,3,4,5];

var b = a.unshift(-2,-1); //a：[-2,-1,1,2,3,4,5] b：7

//注：在IE6.0下测试返回值总为undefined，FF2.0下测试返回值为7，所以这个方法的返回值不可靠，需要用返回值时可用splice代替本方法来使用。

//pop：删除原数组最后一项，并返回删除元素的值；如果数组为空则返回undefined

var a = [1,2,3,4,5];

var b = a.pop(); //a：[1,2,3,4] b：5

//push：将参数添加到原数组末尾，并返回数组的长度

var a = [1,2,3,4,5];

var b = a.push(6,7); //a：[1,2,3,4,5,6,7] b：7

//concat：返回一个新数组，是将参数添加到原数组中构成的

var a = [1,2,3,4,5];

var b = a.concat(6,7); //a：[1,2,3,4,5] b：[1,2,3,4,5,6,7]

//splice(start,deleteCount,val1,val2,)：从start位置开始删除deleteCount项，并从该位置起插入val1,val2,

var a = [1,2,3,4,5];

var b = a.splice(2,2,7,8,9); //a：[1,2,7,8,9,5] b：[3,4]

var b = a.splice(0,1); //同shift

a.splice(0,0,-2,-1); var b = a.length; //同unshift

var b = a.splice(a.length-1,1); //同pop

a.splice(a.length,0,6,7); var b = a.length; //同push

//reverse：将数组反序

var a = [1,2,3,4,5];

var b = a.reverse(); //a：[5,4,3,2,1] b：[5,4,3,2,1]

//sort(orderfunction)：按指定的参数对数组进行排序

var a = [1,2,3,4,5];

var b = a.sort(); //a：[1,2,3,4,5] b：[1,2,3,4,5]

//slice(start,end)：返回从原数组中指定开始下标到结束下标之间的项组成的新数组

var a = [1,2,3,4,5];

var b = a.slice(2,5); //a：[1,2,3,4,5] b：[3,4,5]

//join(separator)：将数组的元素组起一个字符串，以separator为分隔符，省略的话则用默认用逗号为分隔符

var a = [1,2,3,4,5];

var b = a.join("|"); //a：[1,2,3,4,5] b："1|2|3|4|5"

【字符串操作之】将一个字符串拆分成数组→→split方法

String中的split方法将一个字符串拆分成数组。

1、例如，使用空字符可以讲字符串每个分开。

var str:String="abcdefgh";

var arr:Array=str.split("");

trace(arr);

//a,b,c,d,e,f,g,h

2、使用特定符号分割。

var str:String="a_b_c_d";

var arr:Array=str.split("_");

trace(arr);

//a,b,c,d

3、splite还有第二个参数，用来限制放入数组内元素的个数。

var str:String="a_b_c_d_e";

var arr:Array=str.split("_",3);

trace(arr);

//a,b,c

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