Python Program - Check whether a Number is Positive or Negative

A number is said to be positive if it is greater than zero and it is said to be negative if it is less than zero. A number can be checked for zero, positive and negative using if, if-else, nested if-else and short-hand if-else statements.

Method 1: Using If statement

In the example below, if conditional statements are used to check whether a given number is positive or negative.

def CheckNumber(x):
  if x > 0:
    message = "Positive number"
  if x == 0:
    message = "Zero"
  if x < 0:
    message = "Negative number"
  print(message)

CheckNumber(5.5)
CheckNumber(-10.8)

The above code will give the following output:

Positive number
Negative number

Method 2: Using If-else statement

It can also be achieved using If-else conditional statements.

def CheckNumber(x):
  if x > 0:
    message = "Positive number"
  elif x == 0:
    message = "Zero"
  else:
    message = "Negative number"
  print(message)

CheckNumber(5.5)
CheckNumber(-10.8)

The above code will give the following output:

Positive number
Negative number

Method 3: Using Nested If-else statement

The above problem can also be solved using nested if-else conditional statements.

def CheckNumber(x):
  if x >= 0:
    if x > 0:
      message = "Positive number"
    else:
      message = "Zero"
  else:
    message = "Negative number"
  print(message)

CheckNumber(5.5)
CheckNumber(-10.8)

The above code will give the following output:

Positive number
Negative number

Method 4: Using Short hand If-else statement

Short hand if-else conditional statements can also be used here.

def CheckNumber(x):
  message = "Positive number" if x > 0 else \
            "Zero" if x == 0 else "Negative number" 
             
  print(message)

CheckNumber(5.5)
CheckNumber(-10.8)

The above code will give the following output:

Positive number
Negative number