Understanding Why Array.push Fails Inside a Nested For Loop in JavaScript

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Let's consider a specific code snippet that exemplifies the issue. Here’s a function designed to find the longest common prefix among an array of strings:

[[See Video to Reveal this Text or Code Snippet]]

Key Issues Identified

Unexpected Exit: The return statement that is executed when characters do not match will exit the entire function, rather than merely breaking out of the inner loop. This leads to the function terminating prematurely without properly building the answer array.

Logic Flaw: In scenarios where the first character in strings may not match, the algorithm should merely skip to the next character, rather than prematurely exiting.

The Solution: Using Break Instead of Return

To address the above issues, we should modify the logic so that we exit only the inner loop when a discrepancy arises between the characters of reference and check. This will allow the outer loop to continue correctly, yielding a complete array of common characters before finalization.

Here’s the corrected version of the code:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of Changes

Changed Return to Break: The key modification was changing the return statement inside the else clause to a break. This ensures that the function does not exit entirely but rather allows the loop to continue checking further characters in the string.

Result Preservation: This change allows for the preservation of common characters up to the first mismatch, which is crucial for building the intended result.

Conclusion

By applying these principles, you can avoid common pitfalls associated with nested loops and array manipulations in JavaScript, enhancing your programming proficiency.