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Navigating Common Pitfalls & Best Practices with Rest and Spread Operators in JavaScript

Understand Limitations and Optimal Strategies When Wielding ES6’s Versatile Tools

Max N
3 min readApr 2, 2024

Arriving with ES6, Rest and Spread operators revolutionized JavaScript development, bringing unprecedented flexibility and convenience. Yet, misapplication or misunderstanding of these powerful features can lead to pitfalls lurking amid seemingly innocuous lines of code.

Addressing common shortcomings and endorsing established guidelines ensures optimal outcomes, boosting productivity and reducing frustrations.

This article highlights frequently observed stumbling blocks and recommended practices when utilizing Rest and Spread operators in daily workflows.

Practice #1: Preserve Original Argument Order

Despite their syntactical similarity, Rest and Spread operators behave differently when applied to non-iterable primitives (strings, numbers, symbols, bigints, boolean values):

const primitiveString = 'abcde';
const sliceStart = 1;
const sliceEnd = 4;

const slicedSpread = [...primitiveString].slice(sliceStart, sliceEnd).join(''); // bc
const slicedRest = _(primitiveString).rest(sliceStart).take(sliceEnd …

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Max N
Max N

Written by Max N

A writer that writes about JavaScript and Python to beginners. If you find my articles helpful, feel free to follow.

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