Remove or removing Left and Right whitespaces of String in Java

In every standalone application or web application , One concept is always used that is Username/Password .  Now the problem for the programmer to make sure that the user enters the username or password  string without giving any whitespaces before and after  the characters . If our application is used by bad programmer then he/she will use whitespaces in  username and password , and our application go crashing .

To avoid above problem and many other problems which arises due to whitespaces(before/after) the characters of the string .

So our main goal here is to remove all the white spaces that exists, before the string starts and after the string ends . 

Our goal can be achieved by simply using both left trim and right trim in our code. 

for example :

Original String  :  "   *  Alive is awesome  *  "

After using the below java code

Result  :          "*  Alive is awesome  *"   (Note :  White spaces exists only between the characters of                                                                                        the string )

Pseudo Code for the program :

*  Start from the beginning of the string
*  If  character is whitespace then continue reading string
    else break
*  Index value stores at variable i
* Start another loop  from the end of the string
* If  character is whitespace then continue reading string
   else break
*  Index value stores at variable j
* Print the string starting from index i and ending at index j .

Please click here if you want to remove all the whitespaces in the string  (including whitespaces present in between the string characters)


left trim and right trim in the same string

Code :

public class Alltrim {
    static int i,j,k=0;
    public static void main(String[] args) {
        alltrim("  * Java     Hungry  *  ");
    static void alltrim(String s)
            char ch=s.charAt(i);
            if(ch!=' ')
            char ch=s.charAt(j);
            if(ch!=' ')

About The Author

Subham Mittal has worked in Oracle for 3 years .
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