Java

How to Trim a String in Java

Trim is a string manipulation process that is used to make your string clearer and more concise by removing unnecessary parts from it. The trim method in Java allows us to trim the extra spaces from the beginning and the end of the string. In this article, we will provide you with a thorough tutorial on how you can trim a string using a java programming language.

How to trim extra spaces from the string using a Java

We are initializing a public class in which all the code will be written as shown below:

public class StringTrim {
………
}

For this example, in the main function, we have defined some text in java with some extra spaces that we are going to trim in the later code.

String str1 ="        This string contains extra spaces.       ";

If you want to find the total length of the string then you can do that by typing:

int n=str1.length();

Now we are going to display the string along with its length as shown below

System.out.println("String: "+ str1);
System.out.println("Length: "+ n);

There is a built-in trim() function in Java that can be used to trim the unnecessary space from the string and for our code, we can use that by typing:

String str2=str1.trim();
n=str2.length();

In the above code the string is stored in the ‘str1’ variable so we are going to trim that by typing str1.trim() and then saving the result in the new variable which is ‘str2’. Now after trimming we are also going to find the new length of the string and for that, we have used str2.length() function and save the result inside an ‘n’ variable. After that, we are also going to display the new result on the screen using System.out.println() function:

System.out.println("After trimming, String: "+ str2 );
System.out.println("Length of the trimmed string: "+ n);

The complete code is:

public class StringTrim {
    public static void main(String[] args) {
        System.out.println("String trim Example \n");
        //Declare  a string
        String str1 ="        This string contains extra spaces.       ";
        int n=str1.length();    //This line returns the length of string to variable n
        System.out.println("String: "+ str1);
        System.out.println("Length: "+ n);
        String str2=str1.trim();
        n=str2.length();
        System.out.println("After trimming, String: "+ str2 );
        System.out.println("Length of the trimmed string: "+ n);
        //All white spaces like space character, new line character (\n), tab (\t)
        //that are present at the start or at the end of the string are removed.
    }  
}

Terminal in Linux operating system provides the simplest way to implement and execute the code using a java programming language. First, you need to create a java file using a terminal by typing:

$ nano StringTrim.java

The next step is to write and save the code in the Java file:

Note: You need to install the java development kit (JDK) application to execute the java based programs by typing:

$ sudo apt install default-jdk

After saving the file you need to compile it first and then you can execute it by typing:

$ javac StringTrim.java
$ java StringTrim

Conclusion

String trim is a built-in function that is available in the Java library used to remove the extra space from the string. To make strings more clear and concise, you can use a Java built-in function with a name of trim() that we have explained in this article. This article is a detailed guide on how to use Java Trim() function to modify strings.

About the author

Taimoor Mohsin