Category: JavaScript

Sometimes, we want to generate a random number that is 9 digits in length with JavaScript.

In this article, we’ll look at how to generate a random number that is 9 digits in length with JavaScript.

How to generate a random number that is 9 digits in length with JavaScript?

To generate a random number that is 9 digits in length with JavaScript, we use the Math.random method.

For instance, we write

const n = Math.floor(100000000 + Math.random() * 900000000);

to use 100000000 + Math.random() * 900000000 to generate a number that’s 9 digits with decimal places.

Then we call Math.floor to round it down to between 100000000 and 999999999.

Conclusion

To generate a random number that is 9 digits in length with JavaScript, we use the Math.random method.

Sometimes, we want to add an onclick event to a div element with JavaScript.

In this article, we’ll look at how to add an onclick event handler to a div element with JavaScript.

How to add an onclick event handler to a div element with JavaScript?

To add an onclick event handler to a div element with JavaScript, we set the div’s onclick property.

For instance, we write

<div id="thumb0" class="thumbs"></div>

to add a div.

Then we write

const div = document.getElementById("thumb0");
div.onclick = () => {
  div.style.visibility = "visible";
};

to select the div with getElementById.

And then we set its onclick property to the click event handler function, which is called when we click on it.

Conclusion

To add an onclick event handler to a div element with JavaScript, we set the div’s onclick property.

Sometimes, wee want to access iframe elements with JavaScript.

In this article, we’ll look at how to access iframe elements with JavaScript.

How to access iframe elements with JavaScript?

To access iframe elements with JavaScript, we use the contentWindow or contentDocument property.

For instance, we write

<iframe id="one" src="iframe2.html"> </iframe>

to add an iframe.

Then we write

const iframeRef = (frameRef) => {
  return frameRef.contentWindow
    ? frameRef.contentWindow.document
    : frameRef.contentDocument;
};

const inside = iframeRef(document.getElementById("one"));

to define the iframeRef function.

In it, we get the iframe’s document object with frameRef.contentWindow.document or frameRef.contentDocument.

Conclusion

To access iframe elements with JavaScript, we use the contentWindow or contentDocument property.

Sometimes, we want to serialize JavaScript object into JSON string.

In this article, we’ll look at how to serialize JavaScript object into JSON string.

How to serialize JavaScript object into JSON string?

To serialize JavaScript object into JSON string, we use the JSON.stringify method.

For instance, we write

const myObject = new MyClass("1", "text");
const dto = { MyClass: myObject };
console.log(JSON.stringify(dto));

to call JSON.stringify with dto as the argument.

Then a JSON string if returned with the dto object as the string content.

Conclusion

To serialize JavaScript object into JSON string, we use the JSON.stringify method.

Sometimes, we want to export a function with TypeScript.

In this article, we’ll look at how to export a function with TypeScript.

How to export a function with TypeScript?

To export a function with TypeScript, we use the export keyword.

For instance, we write

const someFunc = () => {};

export { someFunc as someFuncName };

to export the someFunc function with name someFuncName.

Conclusion

To export a function with TypeScript, we use the export keyword.