C# Decrement Int

These C# example programs show how decrement works. Syntax and expressions are covered.

Decrement reduces the value of a number.

The decrement operator receives one or two operands. It is written with the characters "-­-" or "-=". We use this operator in any context where statements are permitted.

Increment Int

 

Example. To start, we see a simple program written in the C# language that introduces a local variable integer called i. The character i is a classic name for a loop iteration variable. These variables are also called induction variables.

Int

 

Here: We start the value stored in the variable location with the integer 100. Then, the single decrement operator -­- is applied.

And: This decreases the value by one. Finally we use the -= operator and use several operands with it.

C# program that uses decrement operators

using System;

class Program
{
    static void Main()
    {
	int i = 100;
	// Decrement by one.
	i--;
	Console.WriteLine(i);
	// Decrement by two.
	i -= 2;
	Console.WriteLine(i);
	// Decrement by negative one (add one).
	i -= -1;
	Console.WriteLine(i);
	// Decrement by zero (do nothing).
	i -= 0;
	Console.WriteLine(i);
	// Decrement by itself (results in zero).
	i -= i;
	Console.WriteLine(i);
    }
}

Output

99
97
98
98
0

Bit representation. We have already introduced the concepts of variables and values in this program. The values (such as 100) are actually stored in a bit representation format in the hardware.

And: When you apply a mathematical transformation to the integer, the resulting bit representation is changed in a well-known way as well.

 

 

Pre, post decrement. There are two forms of the decrement by one operator. These are called the post-decrement and pre-decrement operators. These forms are both considered unary operators, meaning they can only receive one operand.

 

Order of evaluation. When you use the post-decrement operator in an expression, the expression is evaluated before the decrement occurs. When you use the pre-decrement operator, it is evaluated after.

C# program that uses two forms of decrement

using System;

class Program
{
    static void Main()
    {
	int i = 5;
	// This evaluates to true because the decrement occurs after the comparison.
	if (i-- == 5)
	{
	    Console.WriteLine(true);
	}
	// This evaluates to true because the decrement occurs before the comparison.
	if (--i == 3)
	{
	    Console.WriteLine(true);
	}
    }
}

Output

True
True

 

Summary. There are many different ways of decrementing variables using the decrement operators in the C# language. Please remember that you can also use expressions to decrement values, even without these operators.