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Will JavaScript detect the keying error in the following example?

publish date: 2022/09/06 01:54:00 GMT+10

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suppose that in a particular JavaScript program, i and x are currently the names of scalar numeric variables and y is currently the name of an array. Furthermore, suppose that the program needs the assignment statement

i = x;

but because of a keying error, it has the assignment statement

i = y;

Yes
No

Correct Answer

No

Explanation

In JavaScript (or any other language that uses dynamic type binding), no error is detected in this statement by the interpreter—the type of the variable named i is simply changed to an array. But later uses of i will expect it to be a scalar, and correct results will be impossible. In a language with static type binding, such as Java, the compiler would detect the error in the assignment i = y, and the program would not get to execution.

Reference

Concepts of Programming languages, 10th ed

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