How many errors are in this code snippet? What’s the output?
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In JavaScript there are two ways to get access to the object properties.
- using the dot
const dog = { name: 'Rex', age: 2, size: 'big' };
console.log(dog.name); // Rex
console.log(dog.age); // 2
console.log(dog.size); // big
- using square brackets
const cat = { name: 'Tom', age: 5, big: false };
console.log(cat['name']); // Tom
console.log(cat['age']); // 5
console.log(cat['big']); // false
Notice, that we’ve used field names as plain strings inside of the square brackets.
If we go to the original question, then the statement
console.log(cat[dog.size]);
Is the same as
console.log(cat['big']);
Which is equivalent to
console.log(cat.big);
In all three cases, we get access to the field big of the object cat.
ANSWER: There are no errors in the code snippet. The value false appears in the console when the code is executed.
Top comments (2)
This is one of those questions that seems so simple once you really think about it. Thanks for the reminder to slow down and think a little longer when I look at these questions 🦄
My pleasure, Ash. Stay tuned for new articles :)