How to trim spaces between characters of string using javascript

[Shrikanth Nekkanti]

I have a function trim(str) which is trimming spaces at begining and after end of string . how to make it to trim spaces between characters of string.

[Eric Pascarello]

Something like

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,"");
}
 
String.prototype.trimAll = function() {
return this.replace(/\s+/g,"");
}

Would call it like this

  var str = "a s d f ";
  var myTrimmedString = str.trimAll();
  alert(myTrimmedString);

I just wrote all that code here, so hopefully there is no typos.

Eric

[Valentin Crettaz]

For trimAll, I would take special care if the function is applied on a string that contains HTML tags, because the space(s) between attribute values are going to be removed.

Example:
"<table border='0' class='myTable'>".trimAll();
would yield
<tableborder='0'class='myTable'>
which is not good.

Instead, I would declare trimAll as follows:
String.prototype.trimAll = function(replaceStr) {
return this.replace(/\s+/g,replaceStr || "");
}

That way, if replaceStr is provided, the spaces will be replaced by it otherwise, the empty string is used by default.

Now,
"<table border='0' class='myTable'>".trimAll(" ");
correctly yields
<table border='0' class='myTable'>

Of course, if you have left and/or right spaces, you'd have to left/right-trim them as well