ArrayIndexOutOfBoundsException when finding words in an array that and with a specific letter-CodePudding

I am trying to find words in an array that end with a letter 'a'. I thought of doing it using two for loops but I keep getting integer out of bounds error.

Could anyone tell me what i am doing wrong?

The code:

Scanner sc = new Scanner(System.in);

System.out.println("Enter text: ");
String text = sc.nextLine();

String[] words = text.split(" ");

for (int i = 0; i < words.length; i  ) {
    words[i] = words[i]   " ";
}

for (int i = 0; i < words.length ; i  ) {
    for (int j = 0; j <= words[i].charAt(j); j  ) {
        if (words[i].charAt(j) == 'a' && words[i].charAt(j   1) == ' ') {
            System.out.println(words[i]);
        }
    }
}

CodePudding user response：

In your second for loop, you are checking against the character at the current position, not the length of the word. Change the condition to words[i].length()to fix it.

CodePudding user response：

In order to check if some words end with character a, we can do the following:

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);

    // Read the input
    System.out.println("Enter text: ");
    String text = sc.nextLine();

    // Split the input by spaces
    String[] words = text.split(" ");

    // Iterate through the array of words and check if any of those ends with "a"
    for (String word : words) {
        if (word.endsWith("a")) {
            System.out.println(word);
        }
    }
}

It would be simple as that, we don't really need an embedded loop.

CodePudding user response：

Try this instead

String[] words = {"apple", "ada", "cat", "material", "recursion", "stacksa"};
for (int i = 0; i < words.length; i  ) {
    // get each word first
    String word = words[I];
    int lenOfWord = word.length();
    // check the last item in the word
    if (word.charAt(lenOfWord - 1) == 'a') {
        System.out.println("Last char is a"   word);
    }
}

CodePudding user response：

You've got too much code for the task, which has lead to a bug. IF you keep the code as simple as possible, you get less bugs.

Delete this, which you don't need.

for (int i = 0; i < words.length; i  ) {
    words[i] = words[i]   " ";
}

And delete all of this:

for (int j = 0; j <= words[i].charAt(j); j  ) {
    if( words[i].charAt(j) == 'a' && words[i].charAt(j   1) == ' '){
        System.out.println(words[i]);
    }
}

instead basing your code on endsWith("a"):

for (String word : words) {
    if (word.endsWith("a")) {
        System.out.println(word);
    }
}

which is easy to read and understand (and thus easier to avoid bugs).

Even simpler, since you don't actually need to reference the array:

String text = sc.nextLine();

for (String word : text.split(" ")) {
    if (word.endsWith("a")) {
        System.out.println(word);
    }
}

CodePudding user response：

Other answers explain the logic via loops. Another approach to do the same could be through Java streams:

Scanner sc = new Scanner(System.in);

System.out.println("Enter text: ");
String text = sc.nextLine();

String[] words = text.split(" ");

Arrays.stream(words).filter(w -> w.endsWith("a")).forEach(System.out::println);