Language: Java

import java.util.*;

public class Main{
	public static void main(String[] args){

		Scanner scan = new Scanner(System.in);
		String sent = scan.nextLine();
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		for(int i = 0; i < 26; i++){
			int cnt = 0;
			for(int j = 0; j < sent.length(); j++){
				char c = sent.charAt(j);
				if(c == alp[i]){
					cnt++;
				}
			}
			System.out.printf("%s : %d\n", alp[i], cnt);
		}
	}
}

Compiler output:
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                ^
  symbol:   variable a
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                   ^
  symbol:   variable b
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                      ^
  symbol:   variable c
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                         ^
  symbol:   variable d
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                            ^
  symbol:   variable e
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                               ^
  symbol:   variable f
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                  ^
  symbol:   variable g
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                     ^
  symbol:   variable h
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                        ^
  symbol:   variable i
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                           ^
  symbol:   variable j
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                              ^
  symbol:   variable k
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                 ^
  symbol:   variable l
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                    ^
  symbol:   variable m
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                       ^
  symbol:   variable n
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                          ^
  symbol:   variable o
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                             ^
  symbol:   variable p
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                ^
  symbol:   variable q
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                   ^
  symbol:   variable r
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                      ^
  symbol:   variable s
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                         ^
  symbol:   variable t
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                            ^
  symbol:   variable u
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                               ^
  symbol:   variable v
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                                  ^
  symbol:   variable w
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                                     ^
  symbol:   variable x
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                                        ^
  symbol:   variable y
  location: class Main
Main.java:8: error: cannot find symbol
		char [] alp = { a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z };
		                                                                                           ^
  symbol:   variable z
  location: class Main
26 errors