JS常用函数汇总

//数字格式转换成千分位 和 去除千分位函数
<script language="javascript" type="text/javascript">
/* 数字格式转换成千分位
 *@param{Object}num
 */
function commafy(num){
   if((num+"").trim()==""){
      return "";
   }
   if(isNaN(num)){
      return "";
   }
   num = num+"";
   if(/^.*\..*$/.test(num)){
      varpointIndex =num.lastIndexOf(".");
      varintPart = num.substring(0,pointIndex);
      varpointPart =num.substring(pointIndex+1,num.length);
      intPart = intPart +"";
       var re =/(-?\d+)(\d{3})/;
       while(re.test(intPart)){
          intPart =intPart.replace(re,"$1,$2");
       }
      num = intPart+"."+pointPart;
   }else{
      num = num +"";
       var re =/(-?\d+)(\d{3})/;
       while(re.test(num)){
          num =num.replace(re,"$1,$2");
       }
   }
    return num;
}
/**
 * 去除千分位
 *@param{Object}num
 */
function delcommafy(num){
   if((num+"").trim()==""){
      return"";
   }
   num=num.replace(/,/gi,'');
   return num;
}
</script>
//最简JS验证码
<script language="javascript" type="text/javascript">
var code ; //在全局 定义验证码
function createCode(){ 
code = "";
var codeLength = 4;//验证码的长度
var checkCode = document.getElementById("checkCodeOld");
checkCode.value = "";
var selectChar = new Array(2, 3, 4, 5, 6, 7, 8, 9, 'A', 'B', 'C', 'D',
'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R',
'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z');
for ( var i = 0; i < codeLength; i++) {
var charIndex = Math.floor(Math.random() * 32);
code += selectChar[charIndex];
}
if (code.length != codeLength) {
createCode();
}
checkCode.value = code;
}
function validate() {
var inputCode = document.getElementById("checkcode").value.toUpperCase();
if (inputCode.length <= 0) {
alert("请输入验证码！");
return false;
} else if (inputCode != code) {
alert("验证码输入错误！");
createCode();
return false;
} else {
document.userlogin.submit();
}
}
</script>