Category: JavaScript

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React Native Answers

How to add absolute position and in a flexbox container in React Native?

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Sometimes, we want to add absolute position and in a flexbox container in React Native.

In this article, we’ll look at how to add absolute position and in a flexbox container in React Native.

How to add absolute position and in a flexbox container in React Native?

To add absolute position and in a flexbox container in React Native, we can set position to 'absolute' and set the left, top, right, and bottom values.

For instance, we write

const styles = StyleSheet.create({
  container: {
    position: "absolute",
    left: 0,
    top: 0,
    right: 0,
    bottom: 0,
  },
});

to set the position to 'absolute'.

And then we set the left, top, right, and bottom values to position the component with the styles in pixels.

Conclusion

To add absolute position and in a flexbox container in React Native, we can set position to 'absolute' and set the left, top, right, and bottom values.

Categories
JavaScript Answers

How to check if an element has event listener on it with JavaScript?

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Sometimes, we want to check if an element has event listener on it with JavaScript.

In this article, we’ll look at how to check if an element has event listener on it with JavaScript.

How to check if an element has event listener on it with JavaScript?

To check if an element has event listener on it with JavaScript, we can call the getEventListeners function in the Chrome developer console.

For instance, we write

getEventListeners(document.querySelector("your-element-selector"));

in the Chrome developer console to select the element we want to check with querySelector.

And then we call getEventListeners with the element to get all the event listeners added to the element.

Conclusion

To check if an element has event listener on it with JavaScript, we can call the getEventListeners function in the Chrome developer console.

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JavaScript Answers

How to check if date is less than 1 hour ago with JavaScript?

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Sometimes, we want to check if date is less than 1 hour ago with JavaScript.

In this article, we’ll look at how to check if date is less than 1 hour ago with JavaScript.

How to check if date is less than 1 hour ago with JavaScript?

To check if date is less than 1 hour ago with JavaScript, we can compare the timestamp difference to the value for one hour in milliseconds.

For instance, we write

const lessThanOneHourAgo = (date) => {
  const HOUR = 1000 * 60 * 60;
  const anHourAgo = Date.now() - HOUR;

  return date > anHourAgo;
};

to define HOUR to be the value of one hour in milliseconds.

Then we use Date.now() - HOUR to get the timestamp in milliseconds for one hour ago.

Finally, we compare the timestamp of date to anHourAgo with

date > anHourAgo

Conclusion

To check if date is less than 1 hour ago with JavaScript, we can compare the timestamp difference to the value for one hour in milliseconds.

Categories
React Answers

How to define more than one style name using CSS modules with React?

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Sometimes, we want to define more than one style name using CSS modules with React.

In this article, we’ll look at how to define more than one style name using CSS modules with React.

How to define more than one style name using CSS modules with React?

To define more than one style name using CSS modules with React, we can put them class names in one string.

For instance, we write

function Footer(props) {
  return (
    <div className={styles.footer}>
      <div className={`${styles.description} ${styles.yellow}`}>
        <p>this site was created by me</p>
      </div>
    </div>
  );
}

to set the className prop of the inner prop to

`${styles.description} ${styles.yellow}`

to apply multiple classes imported from the CSS module.

Conclusion

To define more than one style name using CSS modules with React, we can put them class names in one string.

Categories
JavaScript Answers

How to upload multiple files using form data with JavaScript?

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Sometimes, we want to upload multiple files using form data with JavaScript.

In this article, we’ll look at how to upload multiple files using form data with JavaScript.

How to upload multiple files using form data with JavaScript?

To upload multiple files using form data with JavaScript, we can call the append with the same key for multiple files.

For instance, we write

const { files } = document.getElementById("fileupload");
const formData = new FormData();
for (const image of files) {
  formData.append("files", image);
}

to select the file input with getElementById.

Then we get the selected files with files.

Next, we create the FormData object.

Then we loop through the files with a for-of loop and call formData.append with the 'files' key and add each image to it.

Conclusion

To upload multiple files using form data with JavaScript, we can call the append with the same key for multiple files.