Javascript 5 ways to filter all spaces before and after deletion

Type 1: Cyclic check replacement

// For consumer invocation  
function trim(s){ 
  return trimRight(trimLeft(s)); 
} 
// Remove the white space on the left  
function trimLeft(s){ 
  if(s == null) { 
    return ""; 
  } 
  var whitespace = new String(" \t\n\r"); 
  var str = new String(s); 
  if (whitespace.indexOf(str.charAt(0)) != -1) { 
    var j=0, i = str.length; 
    while (j < i && whitespace.indexOf(str.charAt(j)) != -1){ 
      j++; 
    } 
    str = str.substring(j, i); 
  } 
  return str; 
} 

// Remove the white space on the right  www.ofstack.com 
function trimRight(s){ 
  if(s == null) return ""; 
  var whitespace = new String(" \t\n\r"); 
  var str = new String(s); 
  if (whitespace.indexOf(str.charAt(str.length-1)) != -1){ 
    var i = str.length - 1; 
    while (i >= 0 && whitespace.indexOf(str.charAt(i)) != -1){ 
      i--; 
    } 
    str = str.substring(0, i+1); 
  } 
  return str; 
}     

Type 2: Regular replacement

<SCRIPT LANGUAGE="JavaScript"> 
<!-- 
String.prototype.Trim = function() 
{ 
return this.replace(/(^\s*)|(\s*$)/g, ""); 
} 
String.prototype.LTrim = function() 
{ 
return this.replace(/(^\s*)/g, ""); 
} 
String.prototype.RTrim = function() 
{ 
return this.replace(/(\s*$)/g, ""); 
} 
//--> 
</SCRIPT>

// Remove left space ;
function ltrim(s){
  return s.replace(/(^\s*)/g, "");
}
// Remove right space ;
function rtrim(s){
  return s.replace(/(\s*$)/g, "");
}
// Remove left and right spaces ;
function trim(s){
  return s.replace(/(^\s*)|(\s*$)/g, "");
}

Type 3: Using jquery

$.trim(str) 

The internal implementation of jquery is:

function trim(str){  
  return str.replace(/^(\s|\u00A0)+/,'').replace(/(\s|\u00A0)+$/,'');  
}

Type 4: Using motools

function trim(str){  
  return str.replace(/^(\s|\xA0)+|(\s|\xA0)+$/g, '');  
} 

Fifth: Clipping strings

function trim(str){  
  str = str.replace(/^(\s|\u00A0)+/,'');  
  for(var i=str.length-1; i>=0; i--){  
    if(/\S/.test(str.charAt(i))){  
      str = str.substring(0, i+1);  
      break;  
    }  
  }  
  return str;  
} 

//----------------------------------------------------------
//    Remove spaces before and after strings 
//   Return value: 
//   String after removing spaces 
//----------------------------------------------------------
function trim(param) {
  if ((vRet = param) == '') { return vRet; }
  while (true) {
    if (vRet.indexOf (' ') == 0) {
      vRet = vRet.substring(1, parseInt(vRet.length));
    } else if ((parseInt(vRet.length) != 0) && (vRet.lastIndexOf (' ') == parseInt(vRet.length) - 1)) {
      vRet = vRet.substring(0, parseInt(vRet.length) - 1);
    } else {
      return vRet;
    }
  }
}