Interesting facts about Increment and Decrement operators in Java
Increment operator is used to incrementing a value by 1. There are two varieties of increment operator:
- Post-Increment: Value is first used for computing the result and then incremented.
- Pre-Increment: Value is incremented first and then the result is computed.
Decrement operator is used for decrementing the value by 1. There are two varieties of decrement operators.
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- Post-decrement: Value is first used for computing the result and then decremented.
- Pre-decrement: Value is decremented first and then the result is computed.
Now let us do Interesting facts about Increment and Decrement operators:
- Can only be applied to variables only
- Nesting of both operators is not allowed
- They are not operated over final variables
- Increment and Decrement Operators can not be applied to boolean.
Let us discuss these 4 facts as listed above and do implement them as follows:
Fact 1: Can be applied to variables only
We can apply ++ and — operator only for variables but not for the constant values. If we are trying to apply ++ and — operator on the constant value then we will get a compile-time error which we will be seeing in example 1B after below example as follows:
Example 1:
Java
// Java program to illustrate Increment// and Decrement Operators// Can be Applied to Variables Only// Main classpublic class GFG { // main driver method public static void main(String[] args) { int a = 10; int b = ++a; // Printing value inside variable System.out.println(b); }} |
11
Example 2:
Java
// Java program to Illustrate Increment and Decrement// operators Can be applied to variables only// Main classpublic class GFG { // main driver method public static void main(String[] args) { // Declaring and initializing variable int a = 10; int b = ++a; // This is change made in above program // which reflects error during compilation b = 10 ++; // Printing its value System.out.println(b); }} |
Output:
Fact 2: Nesting of both ++ and — operators are not allowed
Example
Java
// Java program to Illustrate Nesting Can Not be Applied// to Increment and Decrement Operators// Main classpublic class GFG { // Main driver method public static void main(String[] args) { int a = 10; int b = ++(++a); // Printing the value inside variable System.out.println(b); }} |
Output:
Fact 3: Final variables can’t apply increment and decrement operator
The increment and decrement operators can not be applied to final variables because of the simple reason that their value can not be changed.
Example
Java
// Java Program to Illustrate Increment and Decrement// Operators Can not be applied to final variables// Main classpublic class GFG { // MAin driver method public static void main(String[] args) { // Declaring and initializing final variable final int a = 10; int b = ++a; // Trying to print the updated value inside variable System.out.println(b); }} |
Output:
Fact 4: Increment and Decrement Operators can not be applied to boolean
We can apply ++ and — operators for all primitive data types except Boolean type as it only has true and false which even sounds impractical.
Example
Java
// Java program to Illustrate Increment and Decrement// Operators Can not be applied boolean data type// Main classpublic class GFG { // Main driver method public static void main(String[] args) { // Initially declaring boolean as false boolean b = false; b++; // Trying printing the bool value System.out.println(b); }} |
Output:
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