Functional Programming with ReasonML/

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Function Definition

Function Definition

Let's learn the logic and syntax needed to create our first function!

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As we discussed earlier, a function performs a certain task and returns a value. This implies that the function will contain an expression.

The Need for Functions

A function can be used repeatedly, which helps us avoid writing redundant code.

Let’s look at a simple program where we calculate and print the double of an integer:

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let two = 2;
let seven = 7;
let ten = 10;
let doubleOfTwo = two * 2;
Js.log(doubleOfTwo); /* 4 */
let doubleOfSeven = seven * 2;
Js.log(doubleOfSeven); /* 14 */
let doubleOfTen = ten * 2;
Js.log(doubleOfTen); /* 20 */

The code above is redundantly verbose for no reason. The simple steps are:

  1. Calculate the double.
  2. Print its value.
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