[Solved] Given the following code, what will be the output?int[] nums = {1, 2, 3}; Integer[] boxedNums = new Integer[nums.length]; for (int i = 0; i < nums.length; i++) { boxedNums[i] = nums[i]; } System.out.... | Java

Java - Wrapper Classes

Given the following code, what will be the output?

int[] nums = {1, 2, 3};
Integer[] boxedNums = new Integer[nums.length];
for (int i = 0; i < nums.length; i++) {
    boxedNums[i] = nums[i];
}
System.out.println(java.util.Arrays.toString(boxedNums));

ACompilation error due to array assignment

B[null, null, null]

C[1, 2, 3]

D[1, 2, 3, null]

Step-by-Step Solution

Solution:

Step 1: Understand array and autoboxing in loop
nums is int array. boxedNums is Integer array. Loop assigns each int to Integer element, autoboxing each value.
Step 2: Print the Integer array
Arrays.toString prints the Integer array elements as their values: [1, 2, 3]. No nulls because all elements assigned.
Final Answer:
[1, 2, 3] -> Option C
Quick Check:
Autoboxing fills Integer array from int array correctly [OK]

Quick Trick: Autoboxing works element-wise when assigning primitives to wrapper arrays [OK]

Common Mistakes:

Expecting nulls because of object array
Thinking array assignment causes error
Confusing array length or extra elements

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More Java Quizzes

Given the following code, what will be the output?

Step 1: Understand array and autoboxing in loop

Step 2: Print the Integer array

Final Answer:

Quick Check:

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