Category: JavaScript

Sometimes, we want to update all clients using Socket.io and JavaScript.

In this article, we’ll look at how to update all clients using Socket.io and JavaScript.

How to update all clients using Socket.io and JavaScript?

To update all clients using Socket.io and JavaScript, we can use the io.sockets.emit method.

For instance, we write

io.sockets.emit("users_count", clients);

to call io.sockets.emit to emit the 'users_count' event with clients as the payload.

We can also use socket.broadcast.emit to sends a message to everyone except the socket that starts it.

For instance, we write

socket.broadcast.emit("users_count", clients);

to call socket.broadcast.emit to emit the 'users_count' event with clients as the payload.

Conclusion

To update all clients using Socket.io and JavaScript, we can use the io.sockets.emit method.

Sometimes, we want to print specific part of webpage with JavaScript.

In this article, we’ll look at how to print specific part of webpage with JavaScript.

How to print specific part of webpage with JavaScript?

To print specific part of webpage with JavaScript, we can open a new window and print its contents.

For instance, we write

const printInfo = (ele) => {
  const openWindow = window.open("", "title", "attributes");
  openWindow.document.write(ele.previousSibling.innerHTML);
  openWindow.document.close();
  openWindow.focus();
  openWindow.print();
  openWindow.close();
};

to define the printInfo function that takes the ele element.

In it, we call window.open to open the window.

And then we call openWindow.document.write to write the ele‘s content with ele.previousSibling.innerHTML.

We call openWindow.focus to focus on the window.

Next, we call openWindow.print to print the window.

And then we call close to close the window.

Conclusion

To print specific part of webpage with JavaScript, we can open a new window and print its contents.

Sometimes, we want to set radio button status with JavaScript.

In this article, we’ll look at how to set radio button status with JavaScript.

How to set radio button status with JavaScript?

To set radio button status with JavaScript, we set the checked property of the radio button.

For instance, we write

const radioBtn = document.getElementById("theid");
radioBtn.checked = true;

to select the radio button with getElementById.

Then we set the radioBtn.checked property to true to select the radio button.

Conclusion

To set radio button status with JavaScript, we set the checked property of the radio button.

Sometimes, we want to change onclick action with a JavaScript function.

In this article, we’ll look at how to change onclick action with a JavaScript function.

How to change onclick action with a JavaScript function?

To change onclick action with a JavaScript function, we can set the element’s onclick property to a function that runs when we click on the element.

For instance, we write

document.getElementById(`${id}-button`).onclick = () => {
  hideError(id);
};

to select the element with getElementById.

Then we set its onclick property to a function that calls the hideError function.

Conclusion

To change onclick action with a JavaScript function, we can set the element’s onclick property to a function that runs when we click on the element.

Sometimes, we want to get JavaScript select box’s selected text.

In this article, we’ll look at how to get JavaScript select box’s selected text.

How to get JavaScript select box’s selected text?

To get JavaScript select box’s selected text, we can use the select element’s options and selectedIndex properties.

For instance, we write

const sel = document.getElementById("selectBox");
const text = sel.options[sel.selectedIndex].text;

to select the select element with getElementById.

Then we get the index of the selected option with sel.selectedIndex.

Next we use that with sel.options to get the option that’s selected.

And then get the text of the option with the text property.

Conclusion

To get JavaScript select box’s selected text, we can use the select element’s options and selectedIndex properties.