“else if()” versus multiple “if()”s in C#

Question

How do these practically differ?

// Approach one
if (x == 1)
    DoSomething();
else if (x == 2)
    DoSomethingElse();

// Approach two
if (x == 1)
    DoSo         


        

Answer 1

Else if will only be evaluated if the first condition wasn't true. But two consecutive if statements will both be evaluated.

You can easily test this concept in a Python interpreter:

First run this:

Note: In Python elif is used instead of else if

a = 1
if a >= 1:
  print('a is greater than or equal to 1')
elif a<=1:
  print('a is less than or equal to 1')

then run this

a=1
if a >= 1:
  print('a is greater than or equal to 1')
if a<=1:
  print('a is less than or equal to 1')