Merge two strings letter by letter in Java?

Question

Given two strings, A and B, create a bigger string made of the first char of A, the first char of B, the second char of A, the second char of B, and so on. Any le

Answer 1

Another approach using StringBuilder and char[]. Works as long as the first is longer than the second, which is guaranteed by the first method.

public String mixString(String a, String b) {
    if (b.length() > a.length())
        return mixString(new StringBuilder(b), a.toCharArray(), 0);
    return mixString(new StringBuilder(a), b.toCharArray(), 1);
}

public String mixString(StringBuilder ab, char[] b, int start) {
    int i = 0;
    for (char c : b)
        ab.insert(i++*2 + start, "" + c);
    return ab.toString();
}