Related Articles

# Python Program to swap two numbers without using third variable

• Difficulty Level : Hard
• Last Updated : 16 Nov, 2020

Given two variables n1 and n2. The task is to swap the values of both the variables without using third variable.
Examples:

```X : 10
Y : 20

After swapping X and Y, we get :

X : 20
Y : 10

```

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning - Basic Level Course

``` A :  'Hello'
B :  'World'

After swapping A and B, we get :

A :  'World'
B :  'Hello'

```

Method 1 :- Using simple built-in method

```left , right = right , left

```

This method works for any data type values like string, int, float and is easy to use.

## Python

 `# Python code to swap two numbers``# without using another variable`  `x ``=` `5``y ``=` `7` `print` `(``"Before swapping: "``)``print``(``"Value of x : "``, x, ``" and y : "``, y)` `# code to swap 'x' and 'y'``x, y ``=` `y, x` `print` `(``"After swapping: "``)``print``(``"Value of x : "``, x, ``" and y : "``, y)`

Output:

```Before swapping:
Value of x :  5  and y :  7
After swapping:
Value of x :  7  and y :  5

```

Method 2 :- Using Bitwise XOR operator

```x ^= y
y ^= x
x ^= y

```

This method only works for integers and works faster because this method uses bit operation (for same values, output = 0 and for different values, output = 1) .

## Python

 `# Python code to swap two numbers``# using Bitwise XOR method`  `x ``=` `5`  `# x = 0101``y ``=` `10` `# y = 1010` `print` `(``"Before swapping: "``)``print``(``"Value of x : "``, x, ``" and y : "``, y)` `# Swap code``x ^``=` `y ``# x = 1111, y = 1010``y ^``=` `x ``# y = 0101, x = 1111``x ^``=` `y ``# x = 1010, y = 0101` `print` `(``"After swapping: "``)``print``(``"Value of x : "``, x, ``" and y : "``, y)`

Output:

```Before swapping:
Value of x :  5  and y :  10
After swapping:
Value of x :  10  and y :  5

```

Method 3 :- Using Addition and Subtraction Operators

```x = x + y
y = x - y
x = x - y

```

This method works for variables that have numeric values.

## Python

 `# Python code to swap two numbers``# using + and - operators`  `x ``=` `5.4``y ``=` `10.3` `print` `(``"Before swapping: "``)``print``(``"Value of x : "``, x, ``" and y : "``, y)` `# Swap code``x ``=` `x ``+` `y ``# x = 15.7, y = 10.3``y ``=` `x ``-` `y ``# x = 15.7, y = 5.4``x ``=` `x ``-` `y ``# x = 10.3, y = 5.4` `print` `(``"After swapping: "``)``print``(``"Value of x : "``, x, ``" and y : "``, y)`

Output:

```Before swapping:
Value of x :  5.4  and y :  10.3
After swapping:
Value of x :  10.3  and y :  5.4

```

Method 4 :- Using Division and Multiplication Operators

```x = x * y
y = x / y
x = x / y

```

This method works for variables that have numeric values other than 0 .

## Python

 `# Python code to swap two numbers``# using / and * operators`  `x ``=` `5.4``y ``=` `10.3` `print` `(``"Before swapping: "``)``print``(``"Value of x : "``, x, ``" and y : "``, y)` `# Swap code``x ``=` `x ``*` `y ``# x = 55.62, y = 10.3``y ``=` `x ``/` `y ``# x = 55.62, y = 5.4``x ``=` `x ``/` `y ``# x = 10.3, y = 5.4` `print` `(``"After swapping: "``)``print``(``"Value of x : "``, x, ``" and y : "``, y)`

Output:

```Before swapping:
Value of x :  5.4  and y :  10.3
After swapping:
Value of x :  10.3  and y :  5.4

```

Method 4: Using both bitwise operators and arithmetic operators:

## Python3

 `# python program to swap two numbers``# using bitwise addition for swapping`  `  ` `x ``=` `5``;``y ``=` `10``;``  ` `print` `(``"Before swapping: "``) ;``print``(``"Value of x : "``, x, ``" and y : "``, y) ;``  ` `# same as x = x + y``x ``=` `(x & y) ``+` `(x|y) ;``  ` `#vsame as y = x - y``y ``=` `x ``+` `(~y) ``+` `1` `;``  ` `# same as x = x - y``x ``=` `x ``+` `(~y) ``+` `1` `;``  ` `print` `(``"After swapping: "``)``print``(``"Value of x : "``, x, ``" and y : "``, y)` `# This code is contributed by bunnyram19`

Output:

```Before swapping:
Value of x :  5  and y :  10
After swapping:
Value of x :  10  and y :  5
```

My Personal Notes arrow_drop_up