In this article, we will learn about how to write python program to swap two float numbers.

## Getting Started

The task is to swap two float numbers using python programming. For example,

Let’s say **a = 80.1** and **b = 90.4**, then output should be **a = 90.4** and **b = 80.1**.

There are multiple ways to achieve above tasks.

- Using a Temporary Variable
- Using Arithmetic Operations
- Using Tuple Packing and Unpacking
- Using XOR bitwise operation
- Using map Function

## 1. Using a Temporary Variable

Using third variable, we can write python program to swap two float numbers as shown below –

def swap_numbers(a, b): temp = a # store value of a in temp. a = b # store value of b in a. b = temp # store value of temp in b. return a, b # Example usage a = 5.4 b = 10.6 print("Before swap: a =", a, "b =", b) a, b = swap_numbers(a, b) print("After swap: a =", a, "b =", b)

Here,

- There are two float variables
**a**and**b**which we want to swap or interchange. **temp**is temporary variable which is being used to store value of**a**temporarily.

Output:

Before swap: a = 5.4 b = 10.6 After swap: a = 10.6 b = 5.4

## 2. Using Arithmetic Operations

We are going to use subtract i.e. **–** and addition i.e. **+** operations to swap two float numbers in python programming.

Pseudo code to such tasks –

- Define two float variables
**a**and**b**. - Then, get sum of
**a**and**b**. Then, store sum in**a**. - After that, subtract
**b**from**a**. Then, store the difference in**b**. - Then, subtract
**b**from**a**and store in**a**. - Now, value of
**a**and**b**are interchanged value.

Program –

def swap_numbers(a, b): a = a + b # Take sum of a and b and store in a. b = a - b # Subtract b from a and store in b. a = a - b # Subtract b from a and store in a. return a, b # Example usage num1 = 5.04 num2 = 6.01 print("Before swap: num1 =", num1, "num2 =", num2) num1, num2 = swap_numbers(num1, num2) print("After swap: num1 =", num1, "num2 =", num2)

Output:

Before swap: num1 = 5.04 num2 = 6.01 After swap: num1 = 6.01 num2 = 5.04

## 3. Using Tuple Packing and Unpacking

We can also use techniques of tuple packing and unpacking to write python program to swap two float numbers with examples as shown below –

This is simplest way to interchange two float numbers in python.

def swap_numbers(a, b): return b, a # Example usage num1 = 5.32 num2 = 6.43 print("Before swap: num1 =", num1, "num2 =", num2) num1, num2 = swap_numbers(num1, num2) print("After swap: num1 =", num1, "num2 =", num2)

In above code, we are just interchanging the position and return the values.

Output

Before swap: num1 = 5.32 num2 = 6.43 After swap: num1 = 6.43 num2 = 5.32

## 4. Using XOR Bitwise Operation

We can also use **XOR** bitwise operator i.e. **^** to interchange or swap two float numbers in python as shown below –

def swap_numbers(a, b): a = a ^ b b = a ^ b a = a ^ b return a, b # Example usage num1 = 5.12 num2 = 10.43 print("Before swap: num1 =", num1, "num2 =", num2) num1, num2 = swap_numbers(num1, num2) print("After swap: num1 =", num1, "num2 =", num2)

Output:

Before swap: num1 = 5.12 num2 = 10.43 After swap: num1 = 10.43 num2 = 5.12

## 5. Using map Function

We can also use map function in python to interchange or swap two float numbers in python as shown below –

num1 = 65.34 num2 = 1.32 print("Before swap: num1 =", num1, "num2 =", num2) num1, num2 = map(lambda x: num2 if x == num1 else num1, (num1, num2)) print("After swap: num1 =", num1, "num2 =", num2)

Here,

We use the map function with a lambda function. Then, we compare each number with **num1** and replaces it with **num2** if it matches, and vice versa.

Output:

Before swap: num1 = 65.43 num2 = 1.32 After swap: num1 = 1.32 num2 = 65.43

That’s how we can swap two float numbers in python with examples. Learn more about python at official documentation