Easy tutorial for C / C ++ Control statement 1-b (Nested if else statements)

Easy tutorial for C / C ++ Control statement 1-b (Nested if else statements)

Nested if else statements :

- It is a control statement that sets a number of conditions and allows a specific statement to be executed when a certain condition is true. The structure is as follows.

if ('condition 1') {'execute statement 1'}

else if ('condition 2') {'execute statement 2'}
else if ('condition 3') {'execute statement 3'}
...
else {'execute statement 0'}

- If 'condition 1' is satisfied in the first ' if ' statement, 'execute statement 1' is executed. The rest of the statements are not executed at this time.

- If the first 'condition 1' is not satisfied, the next 'else if ' statement is executed and the 'condition 2' is judged again. If 'condition 2' is true, 'execute statement 2' is executed. That is, if 'condition 1' is false and 'condition 2' is true, 'execute statement 2' is executed and the remaining execution statements are not executed.

- You can add multiple else if statements. The last 'else' statement is a statement that is executed when all the above conditions are not satisfied.

Example Code

#include <iostream>

using namespace std;

int main() {

     int a, b;

          a = 10 ;

          b = 20 ;

     if(a > 100){

             cout<<" a > 100 is true !!! "<<endl ;

          } else if(b > 100){

             cout<<" b > 100 is true !!! "<<endl ;

          } else {

             cout<<" Both a > 100 and b > 100 are false !!! "<<endl ;

          }

          return 0;

}

Results:

 Both a > 100 and b > 100 are false !!!

- Since the conditional expression of the first ' if ' statement is false, the statement "a > 100 is true !!!" is not printed and the next 'if else' statement is executed.

- The statement "b > 100 is true !!!" is not also printed because conditional expression of the 'if else' statement is false.

- Since both of the above conditions are false, the last execute statement is executed.