Post-increment vs pre-increment in C (a++ vs ++a)

main.c

#include <stdlib.h>
#include <stdio.h>

int a = 5;

int aplusplus() {
    int temp = a;
    a = a + 1;
    return temp;
}

int plusplusa() {
    a = a + 1;
    return a;
}

int main(int argc, char* argv[]) {
    // printf("a = %d\n", aplusplus());
    // evaluate to 5
    // increment a

    printf("a = %d\n", plusplusa());
    // increment a
    // evaluate to 6

    return 0;
}