We can use if statements when we want the code to do something when a condition is met.
Sequence of an if statement:
| Step 1 | Evaluate condition |
|---|---|
| Step 2 | • If True , execute action • If False , skip action |
Syntax
x = 3
if x >= 2:
print("x is bigger than or equal to 2")
Example
We can use if-else statements when we want the code to do something else if the condition fails.
Sequence of an if-else statement:
| Step 1 | Evaluate condition |
|---|---|
| Step 2 | • If True , execute action • If False , execute another action |
Syntax
x = 30
if x >= 50:
print("x bigger than or equals to 50")
else:
print("x is a number smaller than 50")
Examples
We can use the if-elif-else statement to tell Python to try a different condition if the previous conditions were not met.
Sequence of an if-elif-else statement:
| Step 1 | • If the first condition is True , then execute the first action • If it is False , then test for the second condition |
|---|---|
| Step 2 | • If the second condition is True , then execute the second action • If it is False , execute the final else action |
Syntax
x = 10
if x > 20:
print("x is bigger than 10.")
elif x = 20:
print("x is equals to 20.")
else:
print("x is neither bigger than 10 or equal to 20.")
Example
1. If - Assign 10 to x. If x is bigger than 0, print "x is a positive number".
2. If-else - Assign -50 to y. If x is bigger than 0, print "x is a positive number". Else, print "x is a negative number".
3. If-elif-else - Assign 0 to z. If x is bigger than 0, print "x is a positive number". Else if x is zero, print "x is 0". Else, print "x is a negative number".