10 JavaScript One-Liners Every Developer Should Know (2025 Edition)



This content originally appeared on DEV Community and was authored by Kushyar Rashidzadeh

JavaScript is full of hidden gems. Many times, we end up writing long functions for tasks that can actually be solved in just a single line of code.

Here are 10 clever JavaScript one-liners that can simplify your code and speed up your workflow.

1. Reverse a String

First JS Tip

Split the string into an array, reverse it, and join it back together.

2. Check if a String is a Palindrome

Second JS Tip

Compares the string with its reversed version.

3. Get a Random Number Between Two Values

Third JS Tip

Generates a random integer between min and max.

4. Shuffle an Array

Fourth JS Tip

Uses the array sort() method with a random comparator.

5. Get Unique Values from an Array

Fifth JS Tip

Set automatically removes duplicates.

6. Flatten a Nested Array

Sixth JS Tip

The flat() method with Infinity flattens arrays of any depth.

7. Capitalize the First Letter of a String

Seventh JS Tip

Quick way to make titles and labels look nice.

8. Get Query Parameters from a URL

Eighth JS Tip

Turns query parameters into a clean object.

9. Check if a Number is Even

Ninth JS Tip

Simple modulus check — quick and clean.

10. Generate a Random Hex Color

10th JS Tip

Handy for generating random colors for backgrounds or UI elements.

🎯 Conclusion

These one-liners show how powerful and concise JavaScript can be. Instead of writing 5–10 lines, you can often solve problems in just one line.

👉 Which one was your favorite? Do you know other cool one-liners?
Drop them in the comments — let’s build a collection together!

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This content originally appeared on DEV Community and was authored by Kushyar Rashidzadeh