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Cover image for JS Refactoring Combo: Simplify If-Else Variable Initialization
Lars Grammel for P42

Posted on • Updated on • Originally published at p42.ai

JS Refactoring Combo: Simplify If-Else Variable Initialization

If-statements are often used to initialize variables with different values depending on a condition. This can lead to unnecessary code duplication and can often be shortened with the conditional operator.

Before (Example)

let movedObject;
if (direction === "left") {
  movedObject = moveLeft(original);
} else {
  movedObject = moveRight(original);
}
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Refactoring Steps

Refactor initializing a variable in an if-else statement

💡  The refactoring steps are using P42 JavaScript Assistant v1.99.

  1. Convert the if-else statement into a conditional expression
  2. Merge variable declaration and initialization
  3. Convert let to const

After (Example)

const movedObject = direction === "left"
  ? moveLeft(original)
  : moveRight(original);
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The change to const is only possible if the variable is not re-assigned later. It has the advantage that it communicates the immutability of movedObject.

Discussion (1)

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harithzainudin profile image
Muhammad Harith Zainudin

This is good! Sometimes we don't realise that our code can be shortened. Will surely try to install p42 after this!