C Programming For Loop

Last modified by Microchip on 2023/11/09 09:06

for loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times.


for (expression1; expression2; expression3)

expression1 initializes a loop count variable once at the start of the loop (e.g. i = 0). expression2 is the test condition – the loop will continue while this is true (e.g. i <= 10). expression3 is executed at the end of each iteration – usually to modify the loop count variable (e.g. i++) 

For loop schematic

1 int i;
3 for (i = 0; i < 5; i++)
4 {
5         printf("Loop iteration %d\n", i);
6 }

The expected output for this for loop is:

Loop iteration 0
Loop iteration 1
Loop iteration 2
Loop iteration 3
Loop iteration 4

It is important to mention that any or all of the three expressions in a for loop may be left blank (semi-colons must remain). If expression1 or expression3 are missing, their actions simply disappear. If expression2 is missing, it is assumed to always be true.

Infinite Loops
for loop without any expressions will execute indefinitely (can leave loop via break statement)
Infinite loops