LeetCode/string/StrStr.java
// needle is not part of haystack.
needle is not part of haystack.
needle is not part of haystack .
public int strStr(String haystack, String needle) {
        if (needle.isBlank()) {
            return 0;
        }
        if (haystack.contains(needle)) {
            return haystack.indexOf(needle);
        } else {
            return -1;
        }
    }
public int strStr ( String haystack , String needle ) { if ( needle . isBlank ( ) ) { return 0 ; } if ( haystack . contains ( needle ) ) { return haystack . indexOf ( needle ) ; } else { return - 1 ; } }
needle is not part of haystack.
needle is not part of haystack .