Category: JavaScript Answers

Sometimes, we want to replace single quotes with double quotes in JavaScript.

In this article, we’ll look at how to replace single quotes with double quotes in JavaScript.

How to replace single quotes with double quotes in JavaScript?

To replace single quotes with double quotes in JavaScript, we use the string replace method.

For instance, we write

const a = "[{'column1':'value0','column2':'value1','column3':'value2'}]";
const b = a.replace(/\'/g, '"');

to call a.replace with a regex that replace all single quotes with double quotes.

We use \' to match single quotes.

The g flag makes replace replace all matches.

The string with the replacements done is returned.

Conclusion

To replace single quotes with double quotes in JavaScript, we use the string replace method.

Sometimes, we want to disable click with JavaScript.

In this article, we’ll look at how to disable click with JavaScript.

How to disable click with JavaScript?

To disable click with JavaScript, we set the onclick property to a function that returns false.

For instance, we write

document.getElementById("myElement").onclick = () => {
  return false;
};

to select the element with getElementById.

Then we set its onclick property to a function that returns false.

The function is called when we click on the element.

And it returns false to stop the default click action.

Conclusion

To disable click with JavaScript, we set the onclick property to a function that returns false.

Sometimes, we want to replace or change the heading text inside h3 with JavaScript.

In this article, we’ll look at how to replace or change the heading text inside h3 with JavaScript.

How to replace or change the heading text inside h3 with JavaScript?

To replace or change the heading text inside h3 with JavaScript, we set the innerText property.

For instance, we write

<h3 id="myHeader"></h3>

to add a h3 element.

Then we write

const myHeader = document.querySelector("#myHeader");
myHeader.innerText = "hello";

to select it with querySelector.

Then we change its text content by setting the innerText property.

Conclusion

To replace or change the heading text inside h3 with JavaScript, we set the innerText property.

To access camera from a browser with JavaScript, we use the navigator.mediaDevices.getUserMedia method.

For instance, we write

<video src=""></video>

to add a video element.

Then we write

const front = false;
const video = document.querySelector("video");
const constraints = {
  video: {
    facingMode: front ? "user" : "environment",
    width: 640,
    height: 480,
  },
};

const mediaStream = await navigator.mediaDevices.getUserMedia(constraints);
video.srcObject = mediaStream;
video.onloadedmetadata = (e) => {
  video.play();
};

to select the video element with querySelector.

We get permission for the camera with navigator.mediaDevices.getUserMedia.

And then we set the mediaStream as the src attribute value of the video element if permission is granted.

Finally, we call play to play the captured video.

Sometimes, we want to create a method for a custom object in JavaScript.

In this article, we’ll look at how to create a method for a custom object in JavaScript.

How to create a method for a custom object in JavaScript?

To create a method for a custom object in JavaScript, we set a property to a function.

For instance, we write

const newObj = {
  met1() {
    alert("hello");
  },
};

newObj.met1();

to put the met1 method into the newObj object.

Then we call met1 with newObj.met1();.

Conclusion

To create a method for a custom object in JavaScript, we set a property to a function.