output the last value of the function - Javascript

anonymous
April 5, 2023
134 views
0 votes
2 Answers

I have a written slider function that, when clicked, displays all values in the console

function outputUpdate(vol) {
  let output = document.querySelector('#volume');
  output.value = vol;

  output.style.left = vol - 20 + 'px';
  if (output.value > 9) {
    output.style.left = vol - 30 + 'px';
  }
  if (output.value > 99) {
    output.style.left = vol - 40 + 'px';
  }
  if (output.value > 240) {
    output.style.left = vol - 45 + 'px';
  }
  if (output.value > 430) {
    output.style.left = vol - 50 + 'px';
  }
  if (output.value > 470) {
    output.style.left = vol - 55 + 'px';
  }
  console.log(vol)
}

<div class="slider">
  <output for="fader" id="volume">0</output>
  <input type="range" id="fader" min="0" max="600" value="0" step="1" oninput="outputUpdate(value)">
</div>

but I need to get only the last value from the console

I tried to write a loop inside the function, but it gives me all the values

      for(i= 0; i< output.value; i++){
             vol1 = vol;
        }
        console.log(vol1)

Current output:

added a picture, I need to get only the final value in the console (i.e. in this case 46) and not all values

Answers

If you update the HTML to wrap your <input> and <output> in a <form>, the input and change listeners will allow you to watch for changes and update the value of the output as the slider is moved, but only log the value once the slider is no longer being adjusted.

const form = document.querySelector("form");
const volumeFader = document.getElementById("volume");
const volumeOutput = document.querySelector("output[for='volume']");

function updateOutput() {
  volumeOutput.value = volumeFader.value;
}

function logValue() {
  console.log(volumeOutput.value);
}

form.addEventListener("input", updateOutput);

form.addEventListener("change", logValue);

<form>
  <output for="volume">0</output>
  <input type="range" id="volume" name="volume" min="0" max="100" value="0" step="1">
</form>

From @Pointy’s suggestion.
We have added property to outputUpdate, function. F.Y.I, function is an object in javascript so we can add as many properties as we want, here we have created timerId property to store id, initialized it with default value 0, to avoid TypeError, because clearTimeout() function expects, valid Id.

function outputUpdate(vol) {
  let output = document.querySelector('#volume');
  output.value = vol;
  output.style.left = vol - 20 + 'px';
  if (output.value > 9) {
    output.style.left = vol - 30 + 'px';
  }
  if (output.value > 99) {
    output.style.left = vol - 40 + 'px';
  }
  if (output.value > 240) {
    output.style.left = vol - 45 + 'px';
  }
  if (output.value > 430) {
    output.style.left = vol - 50 + 'px';
  }
  if (output.value > 470) {
    output.style.left = vol - 55 + 'px';
  }

  // Clear any existing timer and create a new one to print the value
  clearTimeout(outputUpdate.timerId);
  outputUpdate.timerId = setTimeout(() => {
    console.log(vol);
  }, 500);
}
// Initialize the timerId property to 0
outputUpdate.timerId = 0;

<div class="slider">
  <output for="fader" id="volume">0</output>
  <input type="range" id="fader" min="0" max="600" value="0" step="1" oninput="outputUpdate(value)">
</div>

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output the last value of the function – Javascript

Answers