String Concatenation
The + operator can be used between strings to combine them. This is called concatenation :
Example
String firstName = "John";
String lastName = "Doe";
System.out.println(firstName + " " + lastName);Note that we have added an empty text (" ") to create a space between firstName and lastName on print.
Concatenation in Sentences
You can use string concatenation to build sentences with both text and variables:
Example
String name = "John";
int age = 25;
System.out.println("My name is " + name + " and I am " + age + " years old.");The concat() Method
You can also use the concat() method to concatenate strings:
Example
String firstName = "John ";
String lastName = "Doe";
System.out.println(firstName.concat(lastName));You can also join more than two strings by chaining concat() calls:
Example
String a = "Java ";
String b = "is ";
String c = "fun!";
String result = a.concat(b).concat(c);
System.out.println(result);Note
While you can use concat() to join multiple strings, most developers prefer the + operator because it is shorter and easier to read.