Three ways to remove spaces in JavaScript

Method 1:
Personally think the best method. It uses regular expressions, which is the core principle.
Secondly, this method uses the prototype attribute of JavaScript

In fact, you can also use a function to implement it without using this attribute. .But it is more convenient to use after doing this.
Let’s take a look at how this attribute is used.

Returns a reference to the prototype of the object type.

objectName.prototype
objectName parameter is the name of the object.

Explanation
Use the prototype property to provide a set of basic functions of the object's class. New instances of an object "inherit" the operations assigned to the object's prototype.

For example, you want to add a method to the Array object that returns the value of the largest element in the array. To accomplish this, declare the function, add it to Array.prototype, and use it.

function array_max( ){
var i, max = this[0];
for (i = 1; i {
if (max max = this[i];
}
return max;
}
Array.prototype.max = array_max;
var x = new Array(1, 2, 3, 4, 5, 6);
var y = x.max( );

After this code is executed, y saves the maximum value in the array x, or 6.

All JScript internal objects have a read-only prototype property. You can add functionality to a prototype as in this example, but the object cannot be assigned a different prototype. However, user-defined objects can be assigned to new prototypes.

The list of methods and properties for each internal object in this language reference indicates which ones are part of the object's prototype and which ones are not.

The following is the original code

Program code

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, "");
}

//-->

Let's take a look at what "/s means" in JS scripts.

s matches any whitespace character, including spaces, tabs, form feeds, etc. Equivalent to [fnrtv].

Please remember that it is lowercase s

Method 2:
Since the method of use is simple, I will not give an example here.

//Javascript space removal function
function LTrim(str){ //Remove the header of the string Space
var i;
for(i=0;i if(str.charAt(i)!=" "&&str.charAt(i)!=" ") break;
}
str = str.substring(i,str .length);
return str;
}
function RTrim(str){
var i;
for(i=str.length-1;i>=0;i--){
if(str.charAt(i )!=" "&&str.charAt(i)!=" ") break;
}
str = str.substring(0,i+1);
return str;
}
function Trim(str){

return LTrim(RTrim(str));

}

Method three:
This method writes functions together and achieves different implementation effects by passing different parameters

if(iType == 0 || iType == 1)
{
while(sTmpStr == ' ')
{
++i
sTmpStr = sInputString.substr(i,1)
}
sInputString = sInputString.substring(i)
}

if(iType == 0 || iType == 2)
{
sTmpStr = ' '
i = sInputString.length
while(sTmpStr == ' ')
{
--i
sTmpStr = sInputString.substr(i ,1)
}
sInputString = sInputString.substring(0,i+1)
}
return sInputString
}

var sR0 = cTrim(" T e s t ",0)
var sR1 = cTrim(" T e s t ", 1)
var sR2 = cTrim(" T e s t ",2)
document.write("R0 = '" + sR0 + "'
")
document.write("R1 = '" + sR1 + " '
")
document.write("R2 = '" + sR2 + "'
")
//-->