JavaScript Increment and Decrement Operators

JavaScript provides a variety of operators to evaluate mathematical and logical operators and expressions in your programs. Increment and decrement operators are two kinds of unary operators in JavaScript that add or subtract a value of 1 from an operand. The purpose of this article is to describe the concept of these two unary operators in detail.

In other words, in JavaScript, increment and decrement operators return the value after adding 1 or subtracting 1 (-1). Throughout this article, we will use the word "operand" a lot. The operand is the amount of work to be done. For example, the mathematical equation 3 + 5, 3 and 5 are operands and operators.

The increment and decrement operators are utilized only with integer variables and operators with numeric values. It cannot be utlized with variables consisting of character or string values. Increment and decrement operators can be used in prefix and postfix positions. The position of the increment/decrement statement in the program statement determines how the statement behaves.

The job of a postfix operator is more important than the job of a prefix operator. Postfix operators are compared using left-to-right associativity and prefix operators are compared using right-to-left associativity.

Syntax:

Let x be the operand.

Increment:

Decrement:

The ++/ -- operators can be used before or after the operator. Here's how it looks in your code:

Increment Operator

The primary purpose of increment operators is to add one to the variable's numerical count. The symbol "++" in a programming language designates an increment operator.

Syntax:

Pre-Increment Operator:

Post-Increment Operator:

Example

Here is an example in which the values return when the operator (prefix increment) is applied before the operand.

Code

Output

In this case, the value is increased and then decreased.

Example

Here, we'll see the value that results from applying the increment operator (postfix increment) after the operand.

Code

Output

The value is incremented after it is first returned.

Code

Output

The number ++x is printed. Since the value is a prefix increment, the value is initially increased by 1, and then the result is returned and printed. Because of the change in value, console.log(a) produced the value 5.

Continue entering x++, Since the value is a postfix increment, it returns the value before it was increased by 1. console.log(a) produced the value 6 due to the change in value.

Decrement Operator

The Decrement Operator's primary job is to reduce the variable's numerical count by a factor of 1. The symbol "- -" in programming languages represents the Decrement Operator.

The decrement operator in JavaScript is used to reduce a variable's value by one. Whether the decrement operator was on the left (prefix decrement) or the right (postfix decrement) determines the value returned by the operand. The value is decremented by one and then returned if the operator is used before the operand; otherwise, the value is returned first and then decremented.

The decrement operator is restricted to properties of variables and objects; it cannot be applied to other types of references. Moreover, chaining the decrement operator is not possible.

Syntax:

Pre-Decrement Operator:

Post-Decrement Operator:

Example

Here, we'll see the value that results from applying the decrement operator (postfix decrement) after the operand.

Code

Output

It is evident that the value is first returned and then decreased.

Example

Here, we'll see the values obtained when the operator (prefix decrement) is applied before the operand.

Code

Output

In this case, the value is returned after being decreased.

Conclusion

1. There seems to be no difference between using prefixes and suffixes. This is where the problem arises.
2. Unlike other operators that have no side effects and easily return a new value, increment and decrement do not only return a value but also perform a change.
3. When using prefix, the variable is modified first and then returned.
4. When using postfix, the variable is modified first and then the value is altered.