Getting length of array returned by a regex?

Question

Hello I am practicing JavaScript and I got in a little problem I can’t figure out: I’m trying to get an array containing all occurrences from a regex in JavaScript and I’m doing something like this:
var str = “This IS a trY”;
var pattern = /[A-Z]/g;
var matches = str.match(pattern);

And till now it all works because if I do console.log(matches) it will print out something like this
(
T,
I,
S,
Y
)
Just like it usually do with arrays, so I am assuming that in this case the match method is returning an array with all occurrences from the regex.
The problem is that I would like to get the length of this array, but if I do matches.length as we usually do for an array I will get an error... so should I assume that the method is not actually returning an array? Is there a better way to do what I’m trying to do?

Answer 1

Sekiro

I find your follow question somewhat confusing, and I apologize for that.
I sometimes use w3school as a reference source, it may help be of some help to you.
https://www.w3schools.com/jsref/jsref_obj_regexp.asp
https://code.sololearn.com/WrZG4qY1D6E8/#js

Answer 2

Sekiro

You can use the array method isArray() to check if an object is an array or not. /[A-Z]/g does return an array of the matches found, so you can use the property length to get the number of an element within an array.

var str = "This IS a tyY";
var pattern = /[A-Z]/g;
var matches = str.match(pattern);

console.log(Array.isArray(matches));
matches.forEach(item=>console.log(item));
console.log(matches.length);

Answer 3

Thank you ODLNT for your answer! I tried that and it works, but only when there is an occurence of the given pattern, if nothing is found I get an error: null reference cannot evaluate forEach, or something alike..
Is there no way to get an array with all occurences of a given pattern from a regex? And also I’d like it to includes duplicates as well...
for example for the string: ThT huO
find all capital letters and get an array that will result like this:
[T, T, O]

Answer 4

Thank you ODLNT ! I solved my problem, after reading your code I realized that I was trying to get the results of the match without checking if there actually was at least one match, so I was getting an error! I apologize for my messy questions 😅
Thanks again!