How Can I Tell if a Variable Represents a Function in JavaScript?

Determining Function Type for Variables in JavaScript

In JavaScript, variables can hold values of various types, including functions. To determine if a variable refers to a function, you can utilize the typeof operator.

The question presents a scenario where a variable named a is defined as a function. To check if a is of function type within a function called foo, you can use the following code snippet:

function foo(v) {
  if (typeof v === 'function') {
    // Perform actions if `v` is a function
  }
}
foo(a);

The typeof operator returns a string representing the type of the variable being evaluated. For function types, it returns the value 'function'. By comparing the result to 'function', you can determine if v is a function within the foo function. If this condition is met, the code within the if block will be executed, indicating that a is indeed a function.

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