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Esraa Refaat
Esraa Refaat

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Javascript Questions

What's the output?

let c = { greeting: 'Hey!' };
let d;

d = c;
c.greeting = 'Hello';

A: Hello
B: Hey!
C: undefined
D: ReferenceError
E: TypeError

Answer: A

In JavaScript, all objects interact by reference when setting them equal to each other.

First, variable c holds a value to an object. Later, we assign d with the same reference that c has to the object.

Alt Text

When you change one object, you change all of them.

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