<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title></title>
    <style type="text/css">
        .btn
        {
            cursor: pointer;
            height: 25px;
            width: 80px;
            line-height: 23px;
            margin: 0px 4px;
            padding: 0 8px; *padding:02px;text-align:center;display:inline;border-radius:2px;font-size:12px;}</style>
</head>
<body>
    <h1>
        JavaScript自定义函数实现字符串StartWith和EndWith</h1>
    输入：<br />
    <input name="txt_Input" type="text" value="www.slowx.net" id="txt_Input" style="width:99%;" />
    <br />
    字符串：<br />
    <input name="txt_SubInput" type="text" value="www." id="txt_SubInput" style="width:99%;" />
    <br />
    <br />
    <input type="button" id="btn_StartWith" class="btn" value="StartWith" onclick="OkClick(true)" />
    <input type="button" id="btn_EndsWith" class="btn" value="EndsWith" onclick="OkClick(false)" />
    <br />
    <br />
    输出：<br />
    <input name="txt_Output" type="text" id="txt_Output" style="width:99%;" /> </body>
</html>

function StrStartsWith(str, theChar) {
        // StartWith判断 //
        if (str == null || str == "" || theChar == null || theChar == "")
            return false;

var idx = str.indexOf(theChar);

if (idx == 0)
            return true;
        else
            return false;
    }

function StrEndsWith(str, theChar) {
        // EndsWith判断 //
        if (str == null || str == "" || theChar == null || theChar == "")
            return false;

var idx = str.lastIndexOf(theChar);
        var strLen = str.length;
        var theCharLen = theChar.length;

if (idx == strLen - theCharLen)
            return true;
        else
            return false;
    }

function OkClick(isStart) {
        var inputCtrl = document.getElementById("txt_Input");
        var subInputCtrl = document.getElementById("txt_SubInput");
        var outputCtrl = document.getElementById("txt_Output");

var theValue = inputCtrl.value;
        var theChar = subInputCtrl.value;

var theResult = false;

if (isStart)
            theResult = StrStartsWith(theValue, theChar);
        else
            theResult = StrEndsWith(theValue, theChar);

outputCtrl.value = theResult;
    }

</script>

运行脚本复制代码另存代码