Java String concat() with examples

The Java String concat() method concatenates one string to the end of another string. This method returns a string with the value of the string passed into the method, appended to the end of the string. Consider the below illustration:

Illustration:

Input:  String 1   : abc
        String 2   : def
        String n-1 : ...
        String n   : xyz
Output: abcdef...xyz        

Syntax:

public String concat(String anostr)   

Parameter: A string to be concatenated at the end of the other string

Return: Concatenated(combined) string  

Example:

java

// Java program to Illustrate Working of concat() method
// with Strings
// By explicitly assigning result

// Main class
class GFG {

    // Main driver method
    public static void main(String args[])
    {
        // Custom input string 1
        String s = "Hello ";

        // Custom input string 2
        s = s.concat("World");

        // Explicitly assigning result by
        // Combining(adding, concatenating strings)
        // using concat() method

        // Print and display combined string
        System.out.println(s);
    }
}

Output

Hello World

Example 2:

java

// Java program to Illustrate Working of concat() method
// in strings where we are sequentially
// adding multiple strings as we need

// Main class
public class GFG {

    // Main driver method
    public static void main(String args[])
    {
        // Custom string 1
        String str1 = "Computer-";

        // Custom string 2
        String str2 = "-Science";

        // Combining above strings by
        // passing one string as an argument
        String str3 = str1.concat(str2);

        // Print and display temporary combined string
        System.out.println(str3);

        String str4 = "-Portal";
        String str5 = str3.concat(str4);
        System.out.println(str5);
    }
}

Output

Computer--Science
Computer--Science-Portal

As perceived from the code we can do as many times as we want to concatenate strings bypassing older strings with new strings to be contaminated as a parameter and storing the resultant string in String datatype.