if Statement

Where if and only if the expression evaluation is TRUE (nonzero) the statements inside the block will be executed.

Single statement execution

if (expression)
	statement;

Multiple statement execution

if (expression){
	statement__1;
	statement__2;
	statement__3;
	statement__n;
}

Another form of the if statement

It is also possible to use only one variable inside an if statement to evaluate if the code block should be executed.

uint8_t isButtonPressed = 0;

int main(void){
	if (isButtonPressed){
		printf("Turn on the LED\n");
		isButtonPressed = 0;
	}

	return 0;
}

subroutine for button

// Interrupt handler for button press
void ISR_button(void){
	isButtonPressed = 1;
}