#include <stdio.h> int any(char [], char []); main() { char s1[] = "This is a string"; char s2[] = "xyT zig"; printf("Searching for one of \"%s\" in the string \"%s\"\n", s2, s1); printf("Located in position: %d\n", any(s1, s2)); } int any(char s1[], char s2[]) { int pos = -1; int i, j; for (i=0; s2[i] != '\0'; i++) { // process char to find for (j = 0; s1[j] != '\0'; j++) { // process original string if (s2[i] == s1[j]) { // we've found a match! if (pos == -1 || j < pos) { // if first match or earlier match pos = j; } } } } return pos; // remember, first location in an array is 0! }