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Functions
Documenting Functions

TypeScript recognizes JavaScript comment syntax:

// This is a single line comment /* This is a multiline comment */

But it’s common in TypeScript to see a third comment style: documentation comments. A documentation comment is denoted with the first line /** and a final line */. It’s common for each line within the comment to start with an asterisk (*):

/** * This is a documentation comment */

Documentation comments are especially useful for documenting functions. We place a function’s documentation comment in the code directly above the function declaration. We can use special tags within the comment to highlight certain aspects of the function. We can use @param to describe each of the function’s parameters, and we can use @return to describe what the function returns:

/** * Returns the sum of two numbers. * * @param x - The first input number * @param y - The second input number * @returns The sum of `x` and `y` * */ function getSum(x: number, y: number): number { return x + y; } }

Many text editors will helpfully display documentation comments, for example, when hovering over a function name.

Instructions

1.

We grabbed a few functions from earlier exercises. They are sorely missing some documentation comments…

Add a documentation comment makeFruitSalad() function. Your comment should include:

  • a brief description of what the function does
  • a first @param tag for the first parameter
  • a second @param tag for the second parameter
  • a @returns tag explaining what the function returns (in this case, nothing)
2.

Add a documentation comment proclaim() function. Your comment should include:

  • a brief description of what the function does
  • a first @param tag for the first parameter
  • a second @param tag for the second parameter
  • an @returns tag explaining what the function returns (again, in this case, nothing)
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