Thu, 18 Dec 2014 04:02:00 GMT

js数组元素的添加和删除一直比较迷惑，今天�l�于扑ֈ�详细说明的资料了�Q�先�l�个我测试的代码^-^
var arr = new Array();
arr[0] = "aaa";
arr[1] = "bbb";
arr[2] = "ccc";
//alert(arr.length);//3
arr.pop();
//alert(arr.length);//2
//alert(arr[arr.length-1]);//bbb
arr.pop();
//alert(arr[arr.length-1]);//aaa
//alert(arr.length);//1

var arr2 = new Array();
//alert(arr2.length);//0
arr2[0] = "aaa";
arr2[1] = "bbb";
//alert(arr2.length);//2
arr2.pop();
//alert(arr2.length);//1
arr2 = arr2.slice(0,arr2.length-1);
//alert(arr2.length);//0
arr2[0] = "aaa";
arr2[1] = "bbb";
arr2[2] = "ccc";
arr2 = arr2.slice(0,1);
alert(arr2.length);//1
alert(arr2[0]);//aaa
alert(arr2[1]);//undefined

shift�Q�删除原数组�W�一��，�q�返回删除元素的��|��如果数组为空则返�?/span>undefined
var a = [1,2,3,4,5];
var b = a.shift(); //a�Q�[2,3,4,5] b�Q?

unshift�Q�将参数��d��到原数组开��_��q�返回数�l�的长度
var a = [1,2,3,4,5];
var b = a.unshift(-2,-1); //a�Q�[-2,-1,1,2,3,4,5] b�Q?
注：�?span style="font-family: 'Times New Roman';">IE6.0下测试返回值��Mؓundefined�Q�FF2.0下测试返回��gؓ7�Q�所以这个方法的�q�回��g��可靠�Q�需要用�q�回值时可用splice代替本方法来使用�?/span>

pop�Q�删除原数组最后一��，�q�返回删除元素的��|��如果数组为空则返�?span style="font-family: 'Times New Roman';">undefined
var a = [1,2,3,4,5];
var b = a.pop(); //a�Q�[1,2,3,4] b�Q?//不用�q�回的话直接调用��可以了

push�Q�将参数��d��到原数组末尾�Q��ƈ�q�回数组的长�?/span>
var a = [1,2,3,4,5];
var b = a.push(6,7); //a�Q�[1,2,3,4,5,6,7] b�Q?

concat�Q�返回一个新数组�Q�是��参数添加到原数�l�中构成�?/span>
var a = [1,2,3,4,5];
var b = a.concat(6,7); //a�Q�[1,2,3,4,5] b�Q�[1,2,3,4,5,6,7]

splice(start,deleteCount,val1,val2,...)�Q?/span>�?span style="font-family: 'Times New Roman';">start位置开始删�?span style="font-family: 'Times New Roman';">deleteCount��，�q�从该位�|��v插入val1,val2,...

在清�I�数�l�时�Q�只需传�?span style="font-family: 'Times New Roman';">startIndex�?/span>

如果不删除所有元素，再传�?span style="font-family: 'Times New Roman';">deleteCount参数�?/span>

splice�q�具有先删除后添加的功能�Q�即先删除几个元素，然后在删除的位置再添加若�q�元素，删除与添加的元素的个数没有必��ȝ��{�，�q�时�?span style="font-family: 'Times New Roman';">deleteCount也是要用到的�?/span>
var a = [1,2,3,4,5];
var b = a.splice(2,2,7,8,9); //a�Q�[1,2,7,8,9,5] b�Q�[3,4]
var b = a.splice(0,1); //同shift
a.splice(0,0,-2,-1); var b = a.length;//�?span style="font-family: 'Times New Roman';">unshift
var b = a.splice(a.length-1,1);//�?span style="font-family: 'Times New Roman';">pop
a.splice(a.length,0,6,7); var b = a.length; //�?span style="font-family: 'Times New Roman';">push

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

sort(orderfunction)�Q?/span>按指定的参数�Ҏ��l�进行排�?/span>
var a = [1,2,3,4,5];
var b = a.sort(); //a�Q�[1,2,3,4,5] b�Q�[1,2,3,4,5]

slice(start,end)�Q?/span>�q�回从原数组中指定开始下标到�l�束下标之间的项�l�成的新数组
var a = [1,2,3,4,5];
var b = a.slice(2,5); //a�Q�[1,2,3,4,5] b�Q�[3,4,5]

join(separator)�Q?/span>��数�l�的元素�l��v一个字�W�串�Q�以separator为分隔符�Q�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�Q�[1,2,3,4,5] b�Q?1|2|3|4|5"

再给个利用数�l�模�?span style="font-family: 'Times New Roman';">javaStringBuffer处理字符串的�Ҏ��Q?/span>

/**
* 字符串处理函�?/span>
*/
function StringBuffer() {
var arr = new Array;
this.append = function(str) {
arr[arr.length] = str;
};

this.toString = function() {
return arr.join("");//�?span style="font-family: 'Times New Roman';">append�q�来的数�l?span style="font-family: 'Times New Roman';">ping成一个字�W�串
};
}

今天在应用中�H�然发现join是一�U�把数组转换成字�W�串的好�Ҏ��Q�故��装成对象��用了�Q?/span>

/**
*把数�l��{换成特定�W�号分割的字�W�串
*/
function arrayToString(arr,separator) {
if(!separator) separator = "";//separator为null则默认�ؓ�I?/span>
return arr.join(separator);
}

/**
* 查找数组包含的字�W�串
*/
function arrayFindString(arr,string) {
var str = arr.join("");
return str.indexOf(string);
}

�Ҏ��?/a> 2014-12-18 12:02 发表评论

Thu, 18 Jun 2009 09:11:00 GMT

1<script language="javascript">
2var total=10;
3  function selectOrNot(checkBox) {
4   if (checkBox.checked) {
5  selectAll();
6 } else {
7  disSelectAll();
8 }
9  }
10//全�?/span>
11    function selectAll(){
12   for(var i=0;i<total;i++){
13  var checkbox = document.getElementById("checkbox_"+i);
14  if (!checkbox.checked) {
15   checkbox.checked = !checkbox.checked;
16  }
17 }
18  }
19//全不�?/span>
20  function disSelectAll(){
21   for(var i=0;i<total;i++){
22  var checkbox = document.getElementById("checkbox_"+i);
23  if (checkbox.checked) {
24   checkbox.checked = !checkbox.checked;
25  }
26 }
27  }
28//反�?/span>
29    function reverseSelect(){
30   for(var i=0;i<total;i++){
31  var checkbox = document.getElementById("checkbox_"+i);
32  checkbox.checked = !checkbox.checked;
33 }
34  }
35  //删除选中的文�?/span>
36   function delSelArticle(){
37  var deleteStr = "";
38  deleteStr = getDeleteStr();
39  if(deleteStr == ""){
40   alert("没有选择��M��文章");
41   return;
42  }
43  if(confirm("��定要删除这些文章吗�Q?/span>")){
44   window.location.href = "deleteArticle.action?deleteStr=" + deleteStr + ";";
45  }
46 }
47
48   //�q�回选中的�?/span>
49  function getDeleteStr(){
50   var deleteStr = "";
51   for(var i=0;i<total;i++){
52  var checkbox = document.getElementById("checkbox_"+i);
53  if(checkbox.checked)
54   deleteStr = deleteStr + checkbox.value;
55 }
56 return deleteStr;
57  }
58

HTML代码�Q?br />

1//全选，全不选按�?/span>
2<input type="checkbox" onClick="selectOrNot(this);" />
3
4//分页中的CHECKBOX
5<input type="checkbox" id="checkbox_${i-1}" value="${subpage.classId}"/>

�Ҏ��?/a> 2009-06-18 17:11 发表评论

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