Author: John Au-Yeung

Sometimes, we may run into the ‘RangeError: invalid array length’ when we’re developing JavaScript apps.

In this article, we’ll look at how to fix the ‘RangeError: invalid array length’ when we’re developing JavaScript apps.

Fix the ‘RangeError: invalid array length’ When Developing JavaScript Apps

To fix the ‘RangeError: invalid array length’ when we’re developing JavaScript apps, we should make sure the array length value that we call the Array and ArrayBuffer constructors are called with a valid value.

Also, we should make sure we set the length property of an array to a non-negative integer.

For instance, these are all code with invalid length value passed into the Array and ArrayBuffer constructors:

new Array(Math.pow(2, 40))
new Array(-1)
new ArrayBuffer(Math.pow(2, 32)) 
new ArrayBuffer(-1)

We also can’t set the length property of an array to an invalid number:

let a = [];
a.length = - 1; 

To fix the error, we can write code like:

new Array(100)
new ArrayBuffer(100) 

let a = [];
a.length = - 1; 

Conclusion

To fix the ‘RangeError: invalid array length’ when we’re developing JavaScript apps, we should make sure the array length value that we call the Array and ArrayBuffer constructors are called with a valid value.

Also, we should make sure we set the length property of an array to a non-negative integer.

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.

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.

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.