Question

How can I print the longest number in a string?

Answer 1

size_t maxlen = 0, len;
int i, maxindex = 0;

for (i = 1; i < argc; i++) {
    len = strlen(argv[i]);
    if (len > maxlen) {
        maxlen = len;
        maxindex = i;
    }
}

printf("The longest string is '%s'\n", argv[maxindex]);