Can Java's hashCode produce same value for different strings?

Question

Is it possible to have same hashcode for different strings using java\'s hashcode function?or if it is possible then what is the % of its possibility?

Answer 1

This wouldn't directly answer your question, but I hope it helps.

The below is from the source code of java.lang.String.

/**
 * Returns a hash code for this string. The hash code for a
 * String object is computed as
 * 
 * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
 * 
 * using int arithmetic, where s[i] is the
 * ith character of the string, n is the length of
 * the string, and ^ indicates exponentiation.
 * (The hash value of the empty string is zero.)
 *
 * @return  a hash code value for this object.
 */
public int hashCode() {
    int h = hash;
    int len = count;
    if (h == 0 && len > 0) {
    int off = offset;
    char val[] = value;

        for (int i = 0; i < len; i++) {
            h = 31*h + val[off++];
        }
        hash = h;
    }
    return h;
}