CODEWITHSUNDEEP
java
Murtaza Mohsin
Murtaza Mohsin

Reputation: 102

Return the first index from arraylist where string was found logic confusion

guys so I have this method that I am trying to construct, I am just having a hard time understanding the logic. This is the condition of the method:

public int search(String str) – search the list for parameter str. Searches should work regardless of case. For example, “TOMATO” is equivalent to “tomato.”

Hint: the String class has a method called equalsIgnoreCase. If the string str appears more than once in the ArrayList, return the first index where the string str was found or return -1 if the string str was not found in the ArrayList.

This is what I have so far for my code, I am not sure if this is the right way to do it. My ArrayList is defined as words.

In order to solve this issue, I am thinking of using a foreach statement to iterate through the ArrayList then an If to check if the words match then return the Index value based on the match but I am getting error. The other confusion I am having is how do I only return the first Index value only. Maybe I am doing this wrong. Any help or direction is appreciated.

 public int search(String str)
    {
        for(String s : words)
        if(s.contains(s.equalsIgnoreCase(str)))
            return s.get(s.equalsIgnoreCase(str));
            
    }

Upvotes: 0

Views: 538

Answers (3)

Parag Goel
Parag Goel

Reputation: 78

You can use stream also to resolve this problem:

 public boolean search(List<String> words, String wordToMatch)
 {
    Predicate<String> equalityPred =  s -> s.equalsIgnoreCase(wordToMatch);
    return words.stream().anyMatch(equalityPred);
        
 }

Upvotes: 0

CryptoFool
CryptoFool

Reputation: 23119

The first answer unnecessarily has to search through the list of words to find the index once it has determined that the word is in the list. The code should be able to already know the index. This is the more efficient approach:

public int search(String str) {
    int i = 0;
    for (String s : words) {
        if (s.equalsIgnoreCase(str))
            return i;
        i++;
    }
    return -1;
}

There is also the more classic approach...the way it might have been done before the enhance for loop was added to the Java language:

public int search(String str) {
    for (int i = 0; i < words.size(); i++)
        if (words.get(i).equalsIgnoreCase(str))
            return i;
    return -1;
}

Upvotes: 1

Matt
Matt

Reputation: 111

You actually overcomplicated it a little bit

public int search(String str) {
    for(String s : words) {
        if(s.equalsIgnoreCase(str)) {
            return words.indexOf(s);
        }
    }
    return -1;
}

Since the return method will stop running more code in the function it will always return the first matching word.

Upvotes: 1

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