How to display JavaScript output to my html?

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Summary

The issue at hand is displaying JavaScript output to an HTML page. The user has a JavaScript function that performs a math computation and wants to visualize the result on the front page when a button is pressed. However, the output is either undefined or nothing shows up.

Root Cause

The root cause of this issue is:

  • Incorrect usage of the evaluate property: The evaluate property is not a valid property of an HTML element.
  • Incorrect retrieval of input values: The getElementsByClassName method returns an HTMLCollection, and the evaluate property is not a valid property of this collection.
  • Recursive function call: The showInputs function is calling itself recursively without any termination condition, which can cause a stack overflow.

Why This Happens in Real Systems

This issue can happen in real systems due to:

  • Lack of understanding of JavaScript and HTML: The developer may not have a clear understanding of how to interact with HTML elements using JavaScript.
  • Insufficient testing: The code may not have been thoroughly tested, leading to unexpected behavior.
  • Poor code organization: The code may be poorly organized, making it difficult to identify and fix issues.

Real-World Impact

The real-world impact of this issue is:

  • User frustration: The user may become frustrated if the output is not displayed correctly or if the page crashes.
  • Loss of productivity: The developer may spend a significant amount of time debugging the issue, leading to a loss of productivity.
  • Poor user experience: The issue can lead to a poor user experience, which can negatively impact the reputation of the application or website.

Example or Code

const button = document.getElementById('go');
button.addEventListener('click', function showInputs() {
  const inputV = document.getElementsByClassName('inputs')[0].value;
  document.getElementById('out').innerHTML = inputV;
})

How Senior Engineers Fix It

Senior engineers can fix this issue by:

  • Using the correct properties and methods: Using the correct properties and methods to retrieve input values and display output.
  • Avoiding recursive function calls: Avoiding recursive function calls that can cause a stack overflow.
  • Thoroughly testing the code: Thoroughly testing the code to ensure that it works as expected.

Why Juniors Miss It

Juniors may miss this issue due to:

  • Lack of experience: Juniors may not have enough experience with JavaScript and HTML to identify the issue.
  • Insufficient knowledge: Juniors may not have a thorough understanding of JavaScript and HTML, leading to mistakes.
  • Poor debugging skills: Juniors may not have the necessary debugging skills to identify and fix the issue.