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JavaScript

Posted by Ted Shapera
Ted Shapera
2,035 Points

Test if argument is an array

My attempt to test an argument to see if it is an array:

if (typeof arr === 'array') // where arr was a function parameter

failed miserably!

In a video lesson there was an example: if (typeof name === 'undefined') { ...}

I gather the code challenge is expecting a similar approach but can one test for an array somehow using the typeof operator?

Thanks;

Ted

2 Answers

Riley Hilliard
PLUS
Riley Hilliard
Courses Plus Student 17,771 Points
Riley Hilliard
Riley Hilliard
Courses Plus Student 17,771 Points

This should help.

var value = ["really", "cool", "stuff"];

if (value instanceof Array) {
    console.log('value is Array!');
    } else {
    console.log('Not an array');
}
Ted Shapera
Ted Shapera
2,035 Points
Ted Shapera
Ted Shapera
2,035 Points

Thanks for the reply Riley. I was doing one of the code challenges in which they did an example using typeof. Sometimes it seems that its expected that you use the approach they demonstrated. But I think I prefer your suggestion. Thanks again; Ted