Why do we use array destructuring (square brackets notation) in `useState`?
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Assesses fundamental understanding of React conventions, runtime behavior, and memory/performance considerations.
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Comprehensive Model Answer
Verified Solution
When we declare a state variable with useState, it returns a pair — an array with two items. The first item is the current value, and the second is a function that updates the value. Using [0] and [1] to access them is a bit confusing because they have a specific meaning. This is why we use array destructuring instead.
For example, the array index access would look as follows:
var userStateVariable = useState("userProfile"); // Returns an array pair
var user = userStateVariable[0]; // Access first item
var setUser = userStateVariable[1]; // Access second item
Whereas with array destructuring the variables can be accessed as follows:
const [user, setUser] = useState("userProfile");
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