最常用的JS匯總，精心整理，供大家參考！！！

• //檢查空串
  function isEmpty(str){
   if((str == null)||(str.length == 0)) return (true);
   else return(false);
  }
• //檢查是否未數字
  function isDigit(theNum){  
  var theMask = "0123456789";
  if (isEmpty(theNum)) return(false);
  else if(theMask.indexOf(theNum) == -1) return(false);
  return(true);
  }
• //去掉左空格
  function trimLeft(str){
  if(str.charAt(0) == " "){
  str = str.slice(1);
  str = trimLeft(str);
  }
   return str;
  }
• //去掉右空格
  function trimRight(str){
  if(str.charAt( str.length - 1 ) == " "){
  str = str.slice(0,str.length - 1);
  str = trimRight(str);
  }
   return str;
  }
• //去掉左右空格
  function trim(str){
  return trimLeft(trimRight(str));
  }
• //檢查是否是int
  function isInt(str){    
  if(str==""){
  return (false);
  }
  else{
  for(i=0;i<str.length;i++){
  var chr = str.charAt(i);
  if(!(chr>='0' && chr<='9')){
  return (false);
  }
  }
  }
  return (true);
  }
• //檢查str是小數，它的整數部分不多于i位，小數部分不多于j位
  function isDecimalNoMsg(str,i,j){          
  var dot = str.indexOf(".");
  var dot_last = str.lastIndexOf(".");
  var str_f = "";
  var str_b = "";
  if ( dot != -1 ){
  str_f = str.substring(0,dot);
  } else {
  str_f = str;
  }
• if ( dot_last != -1 ){
  str_b = str.substring(dot+1);
  } else {
  str_b = str;
  }
• if( isInt( str_f ) == false ){
  //alert(strMsg);
  return false;
  } else if ( isInt( str_b ) == false ){
  //alert(strMsg);
  return false;
  } else if ( dot != dot_last ){
  //alert(strMsg);
  return false;
  } else if(dot==0 || dot_last==0){
  //alert(strMsg);
  return false;
  }
• if(str_f.length>i){
  //alert(strMsg);
  return false;
  }
  if(dot!=-1 && str_b.length>j){
  //alert(strMsg);
  return false;
  }
  return true;
  }
• //檢查日期格式Format: 99999999)
  function judgeDateFormat(dateStr){
     var re,r;            
     re = //d{8}/;
     r = dateStr.match(re);          
    return(r);                    
  }
• //檢查時間格式(Format: 999999)
  function judgeTimeFormat(timeStr){
     var re,r;            
     re = //d{6}/;
     r = timeStr.match(re);          
    return(r);
  }
    
  //檢查日期是否合法(Format: YYYYMMDD).
  function validateDate(theStr){   
   if(theStr.length!=8){
   return (false);
   } else {
    if(theStr=="99999999")
   return (true);
    var y = theStr.substring(0,4);
    var m = theStr.substring(4,6);
    var d = theStr.substring(6,8);
    var maxDays = 31;
    if(isInt(m)==false||isInt(d)==false||isInt(y)==false){
     return(false);
    }
    else if (y.length < 4){ return(false);}
    else if (!isBetween(m,1,12)){ return(false);}
    if(m.length!=2){ return(false);}
    else if (m==4||m==6||m==9||m==11)maxDays = 30;
    else if (m==2){
     if(y%4>0)maxDays = 28;
     else if(y%100==0&&y%400>0)maxDays = 28;
     else maxDays = 29;
    }
    if(isBetween(d,1,maxDays)==false){ return(false);}
    if(d.length!=2){ return(false);}
    return(true);
•  }
  }
• //檢查時間是否合法(Format: HHMMSS).
  function validateTime(theStr){   
   if(theStr.length!=6){
   return (false);
   } else {
   if(theStr == "240000"){
   return (true);
   }
    var h = theStr.substring(0,2);
    var m = theStr.substring(2,4);
    var s = theStr.substring(4,6);
    if(isInt(h)==false||isInt(m)==false||isInt(s)==false){
     return(false);
    }
    else if (h.length < 2){ return(false);}
    else if (!isBetween(h,0,23)){ return(false);}
    else if (!isBetween(m,0,59)){ return(false);}
    else if (!isBetween(s,0,59)){ return(false);}
    return true;
    }
  }
  //檢查str包含漢字時最大長度不大于maxLen
  function ChineseLenLimit( str, maxLen){
       var Strs = str;
       var strlength=0;
       var i;
       for ( i=0;i<str.length;i++) {
          if(str.charCodeAt(i)>=1000)
                  strlength += 2;
          else
                  strlength += 1;
       }
       if ( strlength > maxLen ){
       return false;
       }
       return true;
• }
• //檢查val在lo與hi之間
  function isBetween(val,lo,hi){
   if ((val < lo) || (val > hi)){ return(false);}
   else { return(true);}
  }
• // 檢查charC是‘0’～‘9’
  function chkChar(charC) {
  if (charC == null || charC.length == 0) {
  return false;
  }
  if (charC == '0')return true;
  if (charC == '1')return true;
  if (charC == '2')return true;
  if (charC == '3')return true;
  if (charC == '4')return true;
  if (charC == '5')return true;
  if (charC == '6')return true;
  if (charC == '7')return true;
  if (charC == '8')return true;
  if (charC == '9')return true;
  return false;
  }
• // 檢查intI是正整數
  function chkInt(intI) {
  if (intI == null || intI.length == 0) {
  return false;
  }
  for(var i=0;i<intI.length;i++) {
  if (!chkChar(intI.charAt(i))) {
  return false;
  }
  }
  if (intI.charAt(0) == '0') {
  return false;
  }
  return true;
  }
  // 檢查numN是數字
  function chkNumber(numN) {
  if (numN == null || numN.length == 0) {
  return false;
  }
  for(var i=0;i<numN.length;i++) {
  if (!chkChar(numN.charAt(i))) {
  return false;
  }
  }
  if (numN.length > 1 && numN.charAt(0) == '0') {
  return false;
  }
  return true;
  }
  // 檢查錢數小數點后最多2位
  function chkAmount(amtA) {
  if (amtA == null || amtA.length == 0) {
  return false;
  }
  var amtArray = new Array();
  amtArray = amtA.split(".");
  if (amtArray.length > 2) {
  return false;
  }
  if (amtArray.length == 1) {
  if (!chkNumber(amtArray[0])) {
  return false;
  }
  return true;
  }
  if (!chkNumber(amtArray[0])) {
  return false;
  }
  if (amtArray[1].length > 2) {
  return false;
  }
  for(var i=0;i<amtArray[1].length;i++) {
  if (!chkChar(amtArray[1].charAt(i))) {
  return false;
  }
  }
  return true;
  }
  //檢查身份證
  function checkAgentId(agentId){
        if (agentId.length==10){
          if (((agentId.charAt(0)=="A") && (agentId.charAt(1)=="A"))||((agentId.charAt(0)=="A") && (agentId.charAt(1)=="Z"))){
             return true;
  }else{
              checknum1=((agentId.charAt(0)>="A") && (agentId.charAt(0)<="Z"));
              checknum2=((agentId.charAt(1)==1) || (agentId.charAt(1)==2));
              if (checknum2 && checknum1){
                 id1 = agentId.charAt(0);
                 if (id1 == 'A') {id0=1;}
                 else if (id1 == 'B') { id0=10 ;}
                 else if (id1 == 'C') { id0=19 ;}
                 else if (id1 == 'D') { id0=28 ;}
                 else if (id1 == 'E') { id0=37 ;}
                 else if (id1 == 'F') { id0=46 ;}
                 else if (id1 == 'G') { id0=55 ;}
                 else if (id1 == 'H') { id0=64 ;}
                 else if (id1 == 'I') { id0=39 ;}
                 else if (id1 == 'J') { id0=73 ;}
                 else if (id1 == 'K') { id0=82 ;}
                 else if (id1 == 'L') { id0=2  ;}
                 else if (id1 == 'M') { id0=11 ;}
                 else if (id1 == 'N') { id0=20 ;}
                 else if (id1 == 'O') { id0=48 ;}
                 else if (id1 == 'P') { id0=29 ;}
                 else if (id1 == 'Q') { id0=38 ;}
                 else if (id1 == 'R') { id0=47 ;}
                 else if (id1 == 'S') { id0=56 ;}
                 else if (id1 == 'T') { id0=65 ;}
                 else if (id1 == 'U') { id0=74 ;}
                 else if (id1 == 'V') { id0=83 ;}
                 else if (id1 == 'W') { id0=21 ;}
                 else if (id1 == 'X') { id0=3  ;}
                 else if (id1 == 'Y') { id0=12 ;}
                 else if (id1 == 'Z') { id0=30 ;}
                 id2 = id0 + agentId.charAt(1)*8 + agentId.charAt(2)*7 + agentId.charAt(3)*6 + agentId.charAt(4)*5 + agentId.charAt(5)*4 + agentId.charAt(6)*3 + agentId.charAt(7)*2 + agentId.charAt(8)*1 + agentId.charAt(9)*1;
                 if (id2 % 10 == 0){
                    return true;
     }
              }
           }
     }
     return false;
  }
• //轉換從UTF-8 到Big5 或 GB2312
  function Unicode2Str(str){
  var re=/&#[/da-fA-F]{1,5};/ig;
  var arr=str.match(re);
  if(arr==null)return("");
  var size=arr.length;
  var arr2=new Array(size);
  for(var i=0;i<arr.length;i++){
  arr2[i]=String.fromCharCode(arr[i].replace(/[&#;]/g,""));
  }
  for(var i=0;i<arr.length;i++){
  str=str.replace(arr[i],arr2[i]);
  }
  //return(arr.toString().replace(/,/g,""))
  return str;
  }
• //獲得當前客戶端時間 (Format: YYYYMMDD).
  function getCurrentDate(){
  var dateObj= new Date();
  var dateString=dateObj.getFullYear();
  if(dateObj.getMonth()<10){
  dateString=dateString+'0'+dateObj.getMonth();
  }else{
  dateString+=dateObj.getMonth();
  }
  if(dateObj.getDate()<10){
  dateString+='0'+dateObj.getDate();
  }else{
  dateString+=dateObj.getDate();
  }
  return dateString;
  }  
• //居中顯示彈出窗口
  function PopWindowOnCenter(url,title,iwidth,iheight){
  var ileft,itop;
  ileft = (window.screen.width-iwidth)/2;
  itop = (window.screen.height-iheight)/2;
• window.open(url,title,'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,copyhistory=no,width='+iwidth+',height='+iheight+',left='+ileft+',top='+itop);
  }
• //移動選中的成員從objFromId的select到objToId的select
  function moveTo(objFromId,objToId){
  var objFrom = document.getElementById(objFromId);
  var objTo = document.getElementById(objToId);
• var len = objFrom.length;
  for(var i=len-1; i>=0; i--){
  if(objFrom.options[i].selected){
  var j = 0;
  for(j = 0; j < objTo.length; j++){
  if(objFrom.options[i].value == objTo.options[j].value){
  break;
  }
  }
  if(j == objTo.length){//the selected item is not in objTo.
  objFrom.options[i].selected = false;
  var option1 = objFrom.options[i];
  objTo.options.add(new Option(option1.text, option1.value));
  objFrom.options.remove(i);
  }
  objFrom = document.getElementById(objFromId);
  len = objFrom.length;
  }
  }
  }
• //移動全部成員從objFromId的select到objToId的select
  function moveAllTo(objFromId,objToId){
  var objFrom = document.getElementById(objFromId);
  var objTo = document.getElementById(objToId);
• var len = objFrom.length;
  for(var i=len-1; i>=0; i--){
  var j = 0;
  for(j = 0; j < objTo.length; j++){
  if(objFrom.options[i].value == objTo.options[j].value){
  break;
  }
  }
  if(j == objTo.length){//the selected item is not in objTo.
  var option1 = objFrom.options[i];
  objTo.options.add(new Option(option1.text, option1.value));
  objFrom.options.remove(i);
  }
  objFrom = document.getElementById(objFromId);
  len = objFrom.length;
  }
  }
• 
  //屏蔽非數字鍵
  function checkKey(){
  if(event.keyCode<48 || (event.keyCode>57 && event.keyCode<96)
  || event.keyCode>105){
  if(event.keyCode != 8){
  event.returnValue=false;
  }
  }
  }