Return inside loops in Java - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to return the first even number found in the array.

Java

public int findFirstEven(int[] numbers) {
    for (int num : numbers) {
        if (num % 2 == 0) {
            return [1];
        }
    }
    return -1;
}

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Anum + 1

Bnumbers

C0

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Returning the whole array instead of the number.

Returning a fixed number like 0 instead of the found number.

The method returns the first even number found in the array, which is the variable num inside the loop.

2fill in blank

medium

Complete the code to return true if any number in the array is negative.

Java

public boolean hasNegative(int[] numbers) {
    for (int num : numbers) {
        if (num < 0) {
            return [1];
        }
    }
    return false;
}

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Anum

Btrue

Cfalse

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Returning false inside the loop.

Returning the number instead of a boolean.

The method returns true immediately when it finds a negative number.

3fill in blank

hard

Fix the error in the code to return the index of the first zero in the array, or -1 if none found.

Java

public int findFirstZero(int[] arr) {
    for (int i = 0; i < arr.length; i++) {
        if (arr[i] == 0) {
            return [1];
        }
    }
    return -1;
}

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Ai

Barr[i]

C0

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Returning the value arr[i] instead of the index.

Returning a fixed number like 0.

The method should return the index i where the zero is found, not the value at that index.

4fill in blank

hard

Fill both blanks to return the sum of positive numbers in the array.

Java

public int sumPositive(int[] nums) {
    int sum = 0;
    for (int [1] = 0; [2] < nums.length; i++) {
        if (nums[i] > 0) {
            sum += nums[i];
        }
    }
    return sum;
}

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Ai

Bnum

Cj

Dlength

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in initialization and condition.

Using a variable that is not an integer index.

The loop variable i is used for initialization and condition to iterate over the array.

5fill in blank

hard

Fill all three blanks to return true if all numbers in the array are positive.

Java

public boolean allPositive(int[] arr) {
    for (int [1] = 0; [2] < arr.length; [3]++) {
        if (arr[i] <= 0) {
            return false;
        }
    }
    return true;
}

Drag options to blanks, or click blank then click option'

Ai

Bj

Dk

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in the for loop parts.

Using a variable not declared in the loop.

The loop variable i is used consistently for initialization, condition, and increment.