JS去空格，是否是数字和监视文本框内容的方法

来源：互联网发布：charls数据编辑：程序博客网时间：2024/06/04 19:08

JS 判断是否是数字

//判断是否是数字
function IsNum(num){
var reNum=/^/d*$/;
return(reNum.test(num));
}

JS　去空格
--------------------------------------------------
//去左空格;
function ltrim(s){
return s.replace( /^/s*/, "");
}
//去右空格;
function rtrim(s){
return s.replace( //s*$/, "");
}
//左右空格;
function trim(s){
return rtrim(ltrim(s));
}

如果是去掉半角和全角空格就把 /s 替换成 [" "|"　"] 就变成
//去左空格;
function ltrim(s){
return s.replace( /^[" "|"　"]*/, "");
}
//去右空格;
function rtrim(s){
return s.replace( /[" "|"　"]*$/, "");
}
//左右空格;
function trim(s){
return rtrim(ltrim(s));
}

JS　监视文本框
——————————————————————————————————————————————————

<HTML><HEAD>
<script language="JavaScript" type="text/javascript">
var id;
var textLength = 0;
var textValueCopy;
var valParam = "20091020200000100001;20091020200000100002;20091020200000100003;20091020200000100004";
var data = valParam.split(";");

function startCheck() {
id = window.setInterval(checkValue,50);
}
function endCheck() {
clearInterval(id);
}
function checkValue(){

var chkResult = false;
var strInputValues = document.all.t.value;
var len = strInputValues.length;
var strInValue;
//文本框不为空，输入内容有改变，输入为20的倍数
if(len !=0 && textValueCopy != strInputValues && len%20 == 0){
//取到新输入的编号
strInValue = strInputValues.substring(len-20,len);
//比较数据中是否存在新输入的编号
for(i = 0; i < data.length; i++){
if(data[i] == strInValue){
chkResult = true;
break;
}
}
//判断新输入的编号是否重复
var tempV = new Array(len/20);
for(i = 0; i < len/20; i++){
tempV[i] = strInputValues.substring(20*i,20*(i+1));

}
for(i = 0; i < tempV.length-1; i++){
if(tempV[i] == strInValue){
chkResult = false;
break;
}
}
if (!chkResult){
document.all.t.value = strInputValues.substring(0,len-20);
alert("has not match!!!");
}
textLength = document.all.t.value.length;
textValueCopy = document.all.t.value;
}
}

</script>
</HEAD>
<Body onload = "document.all.t.focus();startCheck();">
<textarea cols="50" name="t" rows="10" onfocus="startCheck()"></textarea>
<input type="button" value="停止" onClick="endCheck()"/>
</Body>
</html>