Increment and decrement operators

• In Java increment and decrement operators are used to increase or decrease the value of a variable by 1.
• The following two operators are the increment and decrement operators used.

Operator	Explanation
++	Used to increase the value of a variable by 1.
–	Used to decrease the value of a variable by 1.

• Now let’s see how to use them

i++;     // This is used to increase the value of variable 'i' by 1.

i--;     // This is used to decrease the value of variable 'i' by 1.
    

i++;
// Is similar to,
i = i + 1;

i--;
// Is similar to,
i = i - 1;
    

• An interesting fact is that increment and decrement operators can appear in postfix form and the prefix form.
• Postfix form means when the increment or decrement operator is placed after the variable.
• Prefix form means when the increment or decrement operator is placed before the variable.
• Both methods performs the same function in a slightly different way.

i++;   // Postfix
++i;   // Prefix
    

• The only occasion we can experience the difference is when we call the output of the operator.
• The ‘postfix’ form will give the value of the variable as an output after the increment, while the ‘prefix’ form gives the output value of the variable before the increment.
• The following example will explain that.

// Postfix
int x = 5;
System.out.println("Postfix output = " + x++);

// Prefix
int y = 5;
System.out.println("Prefix output = " + ++y);
    

Postfix output = 5
Prefix output = 6
    

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