cmp() function - Python

cmp() method in Python 2.x compares two integers and returns -1, 0, 1 according to comparison. cmp() does not work in python 3.x. You might want to see list comparison in Python.

Example

# Example 1
print(cmp(3, 4)) 
# Example 2
print(cmp(5, 5)) 
# Example 3
print(cmp(7, 6))  

Output

-1
0
1

Explanation

• In the first example, 3 is smaller than 4, so the function returns -1.
• In the second example, 5 is equal to 5, so it returns 0.
• In the third example, 7 is greater than 6, so it returns 1.

Note:
The cmp function was a built-in function in Python 2 for comparing the values of two objects. 
It has been removed in Python 3 and replaced with the == and is operators, which provide more robust and flexible comparison functionality.

Syntax of cmp() function

cmp(x, y)

Parameters

• x: The first value to compare.
• y: The second value to compare.

Return Type

• 0 if x == y (both are equal).
• 1 if x > y (first value is greater).
• -1 if x < y (first value is smaller).

Example of cmp() function

Checking if a Number is Even or Odd

Program to check if a number is even or odd using cmp function. Approach: Compare 0 and n%2, if it returns 0, then it is even, else its odd. Below is the Python implementation of the above program: 

# Python program to check if a number is  
# odd or even using cmp function  
  
# check 12  
n = 12 
if cmp(0, n % 2):  
    print"odd"
else: 
    print"even" 
      
# check 13     
n = 13 
if cmp(0, n % 2):  
    print"odd"
else: 
    print"even" 

Output

even
odd

Explanation

• The cmp() function was used to compare 0 and n % 2 to check if the number is even or odd.
• In Python 3, you can directly use comparison operators like == to achieve the same result without using cmp().