In the last exercise, we learned basic if-else conditions. If you need a quick refresher, you can review Conditional statements.
In this section, we’ll expand to introduce a new condition called “elif”.
Elif Condition
Elif Keyword represents the “else-if” condition. A real world example would be: If I am really hungry, I will eat a cake, else if I am only a little hungry, I will have an apple, else I won’t eat anything. You can see it is used when you want to try another condition if the first one is not true.
# This is the basic elif syntax
if expression:
statement(s)
elif expression:
statement(s)
else:
statement(s)
Let’s see an example
# This is an example
if 1 > 3:
print('1>3')
elif 1 == 3:
print('1=3')
else:
print('1<3')
Since we can see that the first statement, 1 greater than 3, is false, it evaluates to false. The inside of the if statement will not be executed then. We will then evaluate the elif statement, 1 is equal to 3, which also evaluates to false. The inside of the elif will not be executed. So what is in else will be printed.
Warning: elif is different from if
Let’s see two examples
Example A
# This is Example A of two if statements
if 1 == 1:
print('1=1')
if 3 == 3:
print('3=3')
else:
print('wrong')
Example A will print out:
1 = 1
3 = 3
Example B
# This is Example of elif statements
if 1 == 1:
print('1=1')
elif 3 == 3:
print('3=3')
else:
print('wrong')
Example B will print out:
1 = 1
In Example A we will evaluate the first if statement (1==1) to be true. The inside of first if statement will be executed then. We will then evaluate second if statement (3==3) to be true as well. The inside of second if statement will also be executed.
In Example B we will evaluate the first if statement (1==1) to be true. Then the rest part of elif and else will not be evaluated since if is already correct.
Challenge
Can you utilize the knowledge you learnt in Python-Basics-booleans to make your own example for elif?
You may want to review boolean to finish this challenge.