Category: JavaScript

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JavaScript Answers

How to get the filename from a string path in JavaScript?

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Sometimes, we want to get the filename from a string path in JavaScript.

In this article, we’ll look at how to get the filename from a string path in JavaScript.

How to get the filename from a string path in JavaScript?

To get the filename from a string path in JavaScript, we can use the JavaScript string’s split method and the JavaScript array’s pop method.

For instance, we write:

const nameString = "/app/base/controllers/filename.js";
const fileName = nameString.split("/").pop();
console.log(fileName)

to call split on nameString with '/' to split the nameString path into segments.

Then we call pop to return the last entry from the split string.

Therefore, we should see that fileName is 'filename.js' according to the console log.

Conclusion

To get the filename from a string path in JavaScript, we can use the JavaScript string’s split method and the JavaScript array’s pop method.

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JavaScript Answers

How to check if a string is a palindrome with JavaScript?

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Sometimes, we want to check if a string is a palindrome with JavaScript.

In this article, we’ll look at how to check if a string is a palindrome with JavaScript.

How to check if a string is a palindrome with JavaScript?

To check if a string is a palindrome with JavaScript, we can use the JavaScript string’s split and JavaScript array’s reverse and join methods.

For instance, we write:

const isPalindrome = (s) => {
  return s === s.split("").reverse().join("");
}

console.log(isPalindrome('foobar'))
console.log(isPalindrome('abba'))

to create the isPalindrom function to check the string s is the same as the original after we reversed the letters in it.

We reverse s by splitting it with split with an empty string to return an array of characters in the string.

Then we call reverse to reverse the array.

And we call join with an empty string to join the characters back into a string.

Finally, we return s compared with the reversed version of s with ===.

Therefore, from the console log, we should see false and then true logged respectively.

Conclusion

To check if a string is a palindrome with JavaScript, we can use the JavaScript string’s split and JavaScript array’s reverse and join methods.

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JavaScript Answers

How to Convert a Map to JSON Object with JavaScript?

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Sometimes, we want to convert a map to JSON object with JavaScript.

In this article, we’ll look at how to convert a map to JSON object with JavaScript.

How to Convert a Map to JSON Object with JavaScript?

To convert a map to JSON object with JavaScript, we can use the Object.fromEntries method.

For instance, we write:

const map1 = new Map([
  ['foo', 'bar'],
  ['baz', 12]
]);

const obj = Object.fromEntries(map1);
console.log(obj)

then we get that obj is {foo: 'bar', baz: 12} according to the console log.

Conclusion

To convert a map to JSON object with JavaScript, we can use the Object.fromEntries method.

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Chart.js JavaScript Answers

How to disable everything on hover with Chart.js?

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Sometimes, we want to disable everything on hover with Chart.js.

In this article, we’ll look at how to disable everything on hover with Chart.js.

How to disable everything on hover with Chart.js?

To disable everything on hover with Chart.js, we can set the options.events property to an empty array.

For instance, we write:

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.5.1/chart.min.js"></script>

<canvas id='myChart' style='width: 300px; height: 300px'></canvas>

to add the Chart.js script and canvas.

And we write:

const ctx = document.getElementById('myChart').getContext('2d');
const myChart = new Chart(ctx, {
  type: 'line',
  data: {
    labels: ['Monday', 'Tuesday', 'Wednesday'],
    datasets: [{
      label: '# of Votes',
      data: [12, 19, 3],
      borderWidth: 1,
      borderColor: 'green'
    }]
  },
  options: {
    events: []
  }
});

to select the canvas and add a line chart into it.

We set options.events to an empty array to disable everything on hover.

Now when we hover over the graph, we shouldn’t see any tooltips or hover effects displayed.

Conclusion

To disable everything on hover with Chart.js, we can set the options.events property to an empty array.

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JavaScript Answers jQuery

How to show a “are you sure?” dialog when we click on a link with JavaScript or jQuery?

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Sometimes, we want to show a "are you sure?" dialog when we click on a link with JavaScript or jQuery.

In this article, we’ll look at to show a "are you sure?" dialog when we click on a link with JavaScript or jQuery.

How to show a "are you sure?" dialog when we click on a link with JavaScript or jQuery?

To show a "are you sure?" dialog when we click on a link with JavaScript or jQuery, we can call the confirm function in the click event handler of a link.

For instance, we write:

<a href="/DoSomethingDangerous" class='confirm'>do something dangerous</a>

to add the link.

Then we write:

$(() => {
  $('.confirm').click((e) => {
    return window.confirm("Are you sure?");
  });
});

We select the link with $.

And we call click with the click event handler for the link.

In the click event handler, we call window.confirm with the text we want to show in the dialog.

Now when we click on the link, we see ‘Are you sure?’ displayed.

And we can click OK or Cancel to dismiss it.

Conclusion

To show a "are you sure?" dialog when we click on a link with JavaScript or jQuery, we can call the confirm function in the click event handler of a link.