C Nested If

Nested If

You can also place an if statement inside another if. This is called a nested if statement.

A nested if lets you check for a condition only if another condition is already true.

if (condition1) {
  // code to run if condition1 is true
  if (condition2) {
    // code to run if both condition1 and condition2 are true
  }
}

Example

In this example, we first check if x is greater than 10. If it is, we then check if y is greater than 20:

int x = 15;
int y = 25;

if (x > 10) {
  printf("x is greater than 10\n");

  // Nested if
  if (y > 20) {
    printf("y is also greater than 20\n");
  }
}

Real-Life Example

Nested if statements are useful when you need to test multiple conditions that depend on each other. For example, checking if a person is old enough to vote, and if they are a citizen:

int age = 20;
bool isCitizen = true;

if (age >= 18) {
  printf("Old enough to vote.\n");

  if (isCitizen) {
    printf("And you are a citizen, so you can vote!\n");
  } else {
    printf("But you must be a citizen to vote.\n");
  } 
} else {
  printf("Not old enough to vote.\n");
}

Visualize Nested If

Choose a person below to see which blocks run:

Notes

• You can nest as many if statements as you want, but avoid making the code too deep - it can become hard to read.
• Nested if is often used together with else and else if for more complex decision making.