如何检查一个字符串中是否至少有一个字符组成数组？ （JAVA）

Question

For example you have the String 'Hello World' and you want to check if at least one element of a char array is in the String. This is what my code looks like but it doesnt work somehow... :-/

public boolean check(String toCheck){
    int n = toCheck.length();
    int true_counter = 0;

    for(int i = 0; i < n; i++){
        if(toCheck.indexOf(charArray[i]) != -1){
            true_counter++;;
        }
    }

    if(true_counter > 0)
        return true;
    else
        return false;
}

the char array is part of the class. Can someone help me?

Answer 1

You need to run your loop up to the length of charArray , not up to the length of the String :

int n = charArray.length();

Moreover, you could stop as soon as you find the character, without counting the number of matches:

for(int i = 0; i < n; i++){
    if(toCheck.indexOf(charArray[i]) != -1){
        return true;
    }
}
return false;

If you reach the end of the loop without finding a match, you would get to the return false statement.

Answer 2

You could loop over the char array and return as soon as you find a character in the string.

    for (char character : charArray){
        if (checkString.indexOf(character) != -1){
            return true;
        }   
    }