Program

#include<stdio.h>

int main()
{
	//counter, it can also be declared as 'char'
	int count;
	//initializing counter by 'a'
	count= 'a';
	//definig label
	start:
	printf("%c [%d] ",count,count);
	count++;
	//jumping back to 'stat' if condition is true
	if(count <= 'z')
		goto start;
	return 0;
}

Output

a [97] b [98] c [99] d [100] e [101] f [102] g [103] h [104] 
i [105] j [106] k [107] l [108] m [109] n [110] o [111] p [112] 
q [113] r [114] s [115] t [116] u [117] v [118] w [119] x [120] 
y [121] z [122] 

This is a way, by which we can print ASCII values of all lowercase characters (alphabets), please write through comment, if you have any doubt?