swap() in C++

Syntax of swap() in C++

The syntax of the swap() in C++ is as follows:

Parameters of swap() in C++

Now that we know the syntax of the swap() function in C++ Let's look at the parameters passed to the swap() function in C++.

• a - The variable whose value needs to be swapped with the value of variable b.
• b - The variable whose value needs to be swapped with the value of variable a.

Return Value of swap() in C++

The Return Value of the swap function is nothing. Therefore the swap C++ function has a void return type.

Exceptions of swap() in C++

The swap function in C++ works in most cases and has no exceptions.

Complexity

The swap function in C++ has constant complexity. If the swap function is used on an array of n elements, then the swap function has the complexity of n.

Examples

Now we know the syntax of swap() in C++. Let us look at some examples and understand how to use the swap() function in our programs.

Using std::swap() with variables

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In the above code, The swap function swaps the value stored in variables a and b.

Using std::swap() with Arrays

output

In the above code, The swap function swaps the value stored in the array a and b.

Using std::swap() with Characters

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In the above code, The swap function swaps the char value stored in the array a and b.

Using std::swap() with String

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In the above code, The swap function swaps the value stored in the string a and b.

How to Swap Two Variables in C++ without Using the std

Swapping two numbers using a temporary variable

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In the above code, We created a temporary variable temp to swap the values stored in the variables a and b.

You can learn more about swapping two numbers in the Swapping of Two Numbers in Java article.

Swapping two numbers using an arithmetic operation

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In the above code, We used a basic arithmetic operation to swap the value stored in two variables, a and b.

How Does std::swap() in C++ Work?

The swap C++ function is used to swap the value of two variables. Using the swap C++ function, we need not use a third temporary variable or the Arithmetic Operators method to swap the value stored in two variables. The swap C++ function takes two variables as it's a parameter. The swap C++ function swaps the values stored in the variables, passed as the parameter. The swap C++ function swaps the variable's value and doesn't return anything hence swap C++ function has a void return type.