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How does React make read-only props?

I'm wondering what mechanism they actually use to throw an error when trying to install this.props.a = 1

or something similar.

I ask because when registering the props, I don't see anything like [Getter/Setter]

that, which I assumed is what they were doing.

Thank!

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Good question.

I think that props

is some sort of object value that is marked as const

.

But we can change descendants to any value Object

even if it is marked as const

;



// const also works on objects
const MY_OBJECT = {'key': 'value'};

// Attempting to overwrite the object throws an error - Uncaught TypeError: Assignment to constant variable.
MY_OBJECT = {'OTHER_KEY': 'value'};

// However, object keys are not protected,
// so the following statement is executed without problem
MY_OBJECT.key = 'otherValue'; // Use Object.freeze() to make object immutable

As you can see from the above codes, you can use the Object.freeze () function to make the object immutable.

I think the value is props

set as Object.freeze()

.

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