Javascript tips for removing space functions and regular expressions in the jstrim Function

When processing text box input values in javascript, The & quot; remove blank & quot; function is often used. Anyone who has used jQuery knows that jQuery provides a function such as trim (), which can easily help us achieve this effect. However, if jQuery and other frameworks are not used in the project, js itself does not have such a function. We have to write such a function by ourselves. The specific implementation of the function is as follows:

The Code is as follows:

// For the user to call
Function trim (s ){
Return trimRight (trimLeft (s ));
}
// Remove the left blank
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
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;
}

You only need to call the trim function.
The following is the implementation method using regular expressions:

The Code is as follows: