Category: JavaScript Answers

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JavaScript Answers

How to Fix the ‘RangeError: argument is not a valid code point ‘ Error in Our JavaScript App?

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Sometimes, we may run into the ‘RangeError: argument is not a valid code point’ when we’re developing JavaScript apps.

In this article, we’ll look at how to fix the ‘RangeError: argument is not a valid code point’ when we’re developing JavaScript apps.

Fix the ‘RangeError: argument is not a valid code point’ When Developing JavaScript Apps

To fix the ‘RangeError: argument is not a valid code point’ when we’re developing JavaScript apps, we should make sure that we call the String.fromCodePoint method with a valid code point value.

For instance, the following will throw this error:

String.fromCodePoint('_');      
String.fromCodePoint(Infinity); 
String.fromCodePoint(-1);       
String.fromCodePoint(3.14);     
String.fromCodePoint(3e-2);     
String.fromCodePoint(NaN);

These values aren’t numbers that represent characters in the Unicode character set, so the calls above will all throw errors.

On the other hand, the following won’t throw the error since the arguments are all valid Unicode code point values:

String.fromCodePoint(42);     
String.fromCodePoint(65, 90); 
String.fromCodePoint(0x404);  
String.fromCodePoint(0x2F804);
String.fromCodePoint(194564);
String.fromCodePoint(0x1D306, 0x61, 0x1D307)

Conclusion

To fix the ‘RangeError: argument is not a valid code point’ when we’re developing JavaScript apps, we should make sure that we call the String.fromCodePoint method with a valid code point value.

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JavaScript Answers

How to Fix the ‘InternalError: too much recursion’ Error in Our JavaScript App?

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Sometimes, we may run into the ‘InternalError: too much recursion’ when we’re developing JavaScript apps.

In this article, we’ll look at how to fix the ‘InternalError: too much recursion’ when we’re developing JavaScript apps.

Fix the ‘InternalError: too much recursion’ When Developing JavaScript Apps

To fix the ‘InternalError: too much recursion’ when we’re developing JavaScript app, we should make sure that our recursion has a base case that’s executed.

And when that’s executed, the recursion code stops running.

The ‘InternalError: too much recursion’ error is fired by Firefox when it tries to run infinite recursion code.

In Edge, the Error: Out of stack space error is fired.

And in Chrome, the RangeError: Maximum call stack size exceeded is fired for the same error.

Example, of infinitely recursive code is something like:

const count = (x) => {
  count(x + 1);
}
count (0);

There’s no base case in this code, so count keeps running forever once it’s called.

The error can also be fired when there’s too much recursion in the code.

For instance, if we have:

const count = (x) => {
  if (x >= 1000000000000) {
    return;
  }
  count(x + 1);
};
count(0);

Then count stops running only when x is 1000000000001.

This is too much for the browser to handle, so the browser will fire the error.

Also, we should make sure we don’t have setters that sets the same value as it’s getting.

For instance, if we have:

class Person {
  constructor() {}
  set name(name) {
    this.name = name;
  }
}

Then we also have this error because we’re setting and getting the name property in the name setter.

Conclusion

To fix the ‘InternalError: too much recursion’ when we’re developing JavaScript app, we should make sure that our recursion has a base case that’s executed.

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JavaScript Answers

How to Fix the ‘Error: Permission denied to access property “x” ‘ Error in Our JavaScript App?

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Sometimes, we may run into the ‘Error: Permission denied to access property "x"’ when we’re developing JavaScript apps.

In this article, we’ll look at how to fix the ‘Error: Permission denied to access property "x"’ when we’re developing JavaScript apps.

Fix the ‘Error: Permission denied to access property "x"’ When Developing JavaScript Apps

To fix the ‘Error: Permission denied to access property "x"’ when we’re developing JavaScript apps, we should make sure we don’t try to access an object which we have no permission to access.

For instance, if we try to access an iframe’s document object as follows:

<!DOCTYPE html>
<html>
  <head>
    <iframe id="myframe" src="http://example.com"></iframe>
    <script>
      onload = function() {
        console.log(frames[0].document);
      }
    </script>
  </head>
  <body></body>
</html>

Then we may get this error since we have no permission to access an iframe’s document object in out JavaScript app.

The same-origin policy prevents us from accessing the iframe’s document object to prevent unauthorized access of an external document.

Conclusion

To fix the ‘Error: Permission denied to access property "x"’ when we’re developing JavaScript apps, we should make sure we don’t try to access an object which we have no permission to access.

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JavaScript Answers

How to Load Scripts After the Page has Loaded in JavaScript?

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Sometimes, we want to load scripts after the page has loaded in JavaScript.

In this article, we’ll look at how to load scripts after the page has loaded in JavaScript.

Load Scripts After the Page has Loaded in JavaScript

To load scripts after the page has loaded in JavaScript, we can call the jQuery getScript method after the document has been loaded.

We can also listen to the DOMContentLoaded event with plain JavaScript.

For instance, we can write:

$(document).ready(() => {  
  $.getScript("https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js", () => {  
    console.log("Script loaded and executed.");  
  });  
})

We call getScript in the $(document).ready callback so that it’s run only when the DOM is loaded.

To do the same thing with plain JavaScript, we can listen to the DOMContentLoaded event.

To do this, we write:

document.addEventListener('DOMContentLoaded', () => {  
  const script = document.createElement('script');  
  script.src = 'https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js';  
  document.body.appendChild(script);  
});

We call document.addEventListener to add the event listener.

Then in the event listener, we call document.createElement to create the script element.

And we set the src attribute by setting the src property.

Finally, we call document.body.appendChild to append it to the body.

Conclusion

To load scripts after the page has loaded in JavaScript, we can call the jQuery getScript method after the document has been loaded.

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JavaScript Answers

How to Accept an Unlimited Number of Arguments in a JavaScript Function?

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Sometimes, we want to accept an unlimited number of arguments in a JavaScript function.

In this article, we’ll look at how to accept an unlimited number of arguments in a JavaScript function.

Accept an Unlimited Number of Arguments in a JavaScript Function

To accept an unlimited number of arguments in a JavaScript function, we can use the rest operator in the function signature.

For instance, we write:

const foo = (a, b, ...others) => {
  console.log(a, b);
  for (const val of others) {
    console.log(val);
  }
}

foo(1, 2, 3, 4, 5);

We have the foo function that has the parameters a , b , and others .

others has the 3 dots before it, which is the rest operator.

The 3rd and subsequent arguments that are passed into foo will be put into the others array.

Therefore, a is 1, b is 2, and the for-of loop will log 3, 4, and 5.

Conclusion

To accept an unlimited number of arguments in a JavaScript function, we can use the rest operator in the function signature.