Print Variables

Display Variables

The println() method is often used to display variables.

To combine both text and a variable, use the + character:

Example

String name = "John";
System.out.println("Hello " + name);

You can also use the + character to add a variable to another variable:

Example

String firstName = "John ";
String lastName = "Doe";
String fullName = firstName + lastName;
System.out.println(fullName);

In Java, the + symbol has two meanings:

• For text (strings), it joins them together (called concatenation).
• For numbers, it adds values together.

For numeric values, the + character works as a mathematical operator (notice that we use int (integer) variables here):

Example

int x = 5;
int y = 6;
System.out.println(x + y); // Print the value of x + y

From the example above, here's what happens step by step:

• x stores the value 5
• y stores the value 6
• println() displays the result of x + y, which is 11

Mixing Text and Numbers

Be careful when combining text and numbers in the same line of code. Without parentheses, Java will treat the numbers as text after the first string:

Example

int x = 5;
int y = 6;

System.out.println("The sum is " + x + y);   // Prints: The sum is 56
System.out.println("The sum is " + (x + y)); // Prints: The sum is 11

Explanation:

In the first line, Java combines "The sum is " with x, creating the string "The sum is 5". Then y is added to that string, so it becomes "The sum is 56".

In the second line, the parentheses make sure x + y is calculated first (resulting in 11), so the output is "The sum is 11".