Javascript 常用功能备份

来源：互联网发布：淘宝下单失败怎么回事编辑：程序博客网时间：2024/05/15 23:47

1. Array 数组的清空：

Array.prototype.clear = function() {
this.length = 0;
}

2. Array数组的contains实现:

Array.prototype.contains = function(element) {
            var index = -1;
            for (var i = 0; i < this.length; i++) {
                if (this[i] == element) {
                    return i;
                }
            }
            return index;
        }

3. 字符串转换为Date类型：

//datePattern: 日期格式 e.g. yyyy-MM-dd, dd/MM/yyyy, MM/dd/yyyy...

//dateSeparator:日期格式的分隔符 e.g. -,/... 更好点的是能从日期格式里自动分析出分隔符，查找非数字的应该就是

String.prototype.parseToDate = function(datePattern, dateSeparator) {
            var datePatternArr = datePattern.split(dateSeparator);
            var dateStrArr = this.split(dateSeparator);
            var year, month, date;
            try {
                for (var i = 0; i < datePatternArr.length; i++) {
                    if (datePatternArr[i] == "yyyy" || datePatternArr[i] == "yy") {
                        year = dateStrArr[i];
                    }
                    else if (datePatternArr[i] == "MM" || datePatternArr[i] == "M") {
                        month = dateStrArr[i];
                    }
                    else if (datePatternArr[i] == "dd" || datePatternArr[i] == "d") {
                        date = dateStrArr[i];
                    }
                }
                var parsedDate = new Date();
                parsedDate.setFullYear(year);
                parsedDate.setMonth(month - 1);
                parsedDate.setDate(date);
                return parsedDate;
            }
            catch (e) {
                return this;
            }
        }

4.日期比较：

var s1 = txtEndDateValue.parseToDate(pattern, separator);
var s2 = txtDateValue.parseToDate(pattern, separator);

                    var dataRange = document.getElementById('<%= hfDateRange.ClientID %>').value;
                    if (dataRange == "") {
                        dataRange = 60;
                    }

                    var time = s1.getTime() - s2.getTime();
                    var days = parseInt(time / (1000 * 60 * 60 * 24));
                    if (days > dataRange) {
                        alert("Data range must less than "+dataRange+" days.");
                        needInitUserPicDiv = false;
                        return;
                    }

5.float 取值

//f:需要操作的数值

//dec:需要保留的小数位

function tofloat(f, dec) {
            if (dec < 0) return f;
            result = parseInt(f) + (dec == 0 ? "" : ".");
            f -= parseInt(f);
            if (f == 0)
                for (var i = 0; i < dec; i++) result += '0';
            else {
                for (var i = 0; i < dec; i++) f *= 10;
                result += parseInt(Math.round(f));
            }
            return result;
        }

//判断是否数字可以包括小数点

function isNumber(input)
{
        //var pattern=/^[0-9]+$/;
        var pattern = /^[0-9]+(.[0-9]+)?$/;
        return pattern.exec(input);
}

6.字符串StartWith函数

String.prototype.startWith = function(str) {
            if (str == null || str == "" || this.length == 0 || str.length > this.length)
                return false;
            if (this.substr(0, str.length) == str)
                return true;
            else
                return false;
            return true;
        }

7. 捕获键盘输入(IE and FF)

function keyPress(sender, args) {
                if (args.keyCode == 13) {
                    alter("Enter key pressed");
                    return false;
                }
            }

<asp:TextBox ID="txtDescription" runat="server" onkeypress="return keyPress(this, event)"></asp:TextBox>

8.根据class取对象

function getElementsByClassName(classname, node) {
                    if (!node) node = document.getElementsByTagName("body")[0];
                    var a = []; var re = new RegExp('//b' + classname + '//b');
                    var els = node.getElementsByTagName("*");
                    for (var i = 0, j = els.length; i < j; i++)
                        if (re.test(els[i].className)) a.push(els[i]);
                        return a;
                }

//设置区域的高度e.g. BoxHeights.equalise('half_1','half_2'); half_1为class名

9.asp.net中全选/全不选CheckBoxList控件

function funCheckAllDevice(checkAll) {
            var field = document.getElementById('<%=cblResource.ClientID %>');
            if (field!= null) {
                field = field.getElementsByTagName("INPUT");

                for (var i = 0; i < field.length; i++) {
                    field[i].checked = checkAll;
                }
            }
        }

10.asp.net中取所有选中的CheckBoxList item

var devs = new Array();

var field= document.getElementById('<%=cblResource.ClientID %>');
            if (field!= null) {
                field = field.getElementsByTagName("INPUT");
                for (var i = 0; i < field.length; i++) {
                    if (field[i].checked) {
                        var labelArray = field[i].parentNode.getElementsByTagName('label');
                        if (labelArray.length > 0) {

                                devs.push(labelArray[0].innerText);
                        }
                    }
                }
            }