Python - Swap two numbers without using Temporary Variable

The value of two variables can be swapped without using any temporary variables. The method involves using operators like +, *, / and bitwise.

Example: Using + operator

In the below example, the + operator is used to swap the value of two variables x and y.

def swap(x, y):
print("Before Swap.")
print("x =",x)
print("y =",y)

#Swap technique
x = x + y
y = x - y
x = x - y

print("After Swap.")
print("x =",x)
print("y =",y)

swap(10, 25)


Output

Before Swap.
x = 10
y = 25
After Swap.
x = 25
y = 10


Example: Using * operator

Like + operator, the * operator can also be used to swap the value of two variables x and y.

def swap(x, y):
print("Before Swap.")
print("x =",x)
print("y =",y)

#Swap technique
x = x * y
y = x / y
x = x / y

print("After Swap.")
print("x =",x)
print("y =",y)

swap(10, 25)


Output

Before Swap.
x = 10
y = 25
After Swap.
x = 25
y = 10


Example: Using / operator

Smilarly / operator can also be used to swap the value of two variables x and y.

def swap(x, y):
print("Before Swap.")
print("x =",x)
print("y =",y)

#Swap technique
x = x / y
y = x * y
x = y / x

print("After Swap.")
print("x =",x)
print("y =",y)

swap(10, 25)


Output

Before Swap.
x = 10
y = 25
After Swap.
x = 25
y = 10


Example: Using bitwise operator

The bitwise XOR (^) operator can also be used to swap the value of two variables x and y. It returns 1 when one of two bits at same position in both operands is 1, otherwise returns 0.

def swap(x, y):
print("Before Swap.")
print("x =",x)
print("y =",y)

#Swap technique
x = x ^ y
y = x ^ y
x = y ^ x

print("After Swap.")
print("x =",x)
print("y =",y)

swap(10, 25)


Output

Before Swap.
x = 10
y = 25
After Swap.
x = 25
y = 10