Why returns invalid array for an array?

JavaScript
1

In " The Ultimate JavaScript Mastery Series - Part 1", 14- Exercise 3- Error Handling,

I used the code provided by Mosh in the zip and shown in the video.

I put an array in the parameter, but the console returns “Invalid array”, how to fix this?

This is confusing!

try {
  const numbers = [1, 2, 3, 4]; 
  const count = countOccurrences(null, 1); 
  console.log(count); 
}
catch (e) {
  console.log(e.message);
}
 
function countOccurrences(array, searchElement) {
  if (!Array.isArray(array))
    throw new Error('Invalid array.');

  return array.reduce((accumulator, current) => {
    const occurrence = (current === searchElement) ? 1 : 0;
    return accumulator + occurrence;
  }, 0);
} 

countOccurrences([1, 2], 'a');
2

When you run the code above, it’ll execute the try catch before it gets to your function call, and since you called the function with null on line 3, it threw the error. Throwing an error stops the program so it never gets to the function call on the last line.

3

I changed the null to an array , still returns “Invalid array”

try {
  const numbers = [1, 2, 3, 4]; 
  const count = countOccurrences([1,2,3], 1); 
  console.log(count); 
}
catch (e) {
  console.log(e.message);
}