While loop with syntax and flowchart

The while loop is an entry-controlled loop: the condition is tested first, and the body is executed repeatedly as long as the condition is true. If the condition is false at the start, the body never executes.

Syntax:

initialisation;
while (condition)
{
    statements;
    update;
}

Flowchart:

      [ initialisation ]
              |
        +---->|
        |     v
        | < condition ? >--False--> next statement
        |     | True
        | [ body + update ]
        +-----+

Example:

#include <stdio.h>
int main(void)
{
    int i = 1, sum = 0;
    while (i <= 5)
    {
        sum += i;
        i++;
    }
    printf("Sum of 1 to 5 = %d\n", sum);
    return 0;
}

Output:

Sum of 1 to 5 = 15