Three ways to remove spaces in JavaScript (regular/parameter function/trim)_javascript skills

Method 1:
Personally think it is the best method. It uses regular expressions, which is the core principle.
Secondly, this method uses the prototype attribute of JavaScript
In fact If you don't use this attribute, you can use a function to implement it. But it is more convenient to use it this way.
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.
Description
Use the prototype property to provide a basic set of functionality for an object's class. New instances of an object "inherit" the operations assigned to the object's prototype.

For example, add a method to an 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.

Copy code The code is as follows:

function array_max( ){
var i, max = this[0];
for (i = 1; i < this.length; i )
{
if (max < this[i])
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

Copy the code The code is as follows:

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.

Copy code The code is as follows:

//Javascript space removal function
function LTrim(str){ //Remove the leading spaces of the string
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 3:
This method writes functions together and achieves different effects by passing different parameters

Copy code The code is as follows: