13 JavaScript Tricks to Write Cleaner, Faster Code

1. Multiple expressions in an if statement

Replace a long chain of OR conditions with an includes check on an array.

if (['abc', 'def', 'ghi', 'jkl'].includes(x)) {
  // logic
}

2. Simplify if‑else

When the logic is simple, use a ternary operator or direct boolean assignment.

let test = (x > 10) ? true : false;
// or even
let test = x > 10;

3. Merge variable declarations

Declare variables of the same type in a single statement.

let test1, test2 = 1;

4. Merge variable assignments

Use array destructuring to assign multiple values at once.

let [test1, test2, test3] = [1, 2, 3];

5. && operator for conditional calls

Execute a function only when a variable is truthy.

test1 && callMethod();

6. Arrow functions

Replace a traditional function with a concise arrow function.

const add = (a, b) => a + b;

7. Short function invocation

Choose between two functions with a ternary expression and invoke the result immediately.

(test === 1 ? fun1 : fun2)();

8. Switch shorthand

Map cases to functions in an object and call them dynamically.

const data = {
  1: test1,
  2: test2,
  3: test
};
data[something] && data[something]();

9. Default parameter values

Define defaults directly in the function signature.

const add = (test1 = 1, test2 = 2) => test1 + test2;

10. Spread operator

Merge arrays and copy arrays succinctly.

// merge arrays
const data = [1, 2, 3];
const test = [4, 5, 6, ...data];

// copy array
const test1 = [1, 2, 3];
const test2 = [...test1];

11. Template strings

Build strings with embedded expressions.

const welcome = `Hi ${test1} ${test2}`;

12. Object shorthand

When property names match variable names, omit the key.

let obj = {test1, test2};

13. Find max and min in an array

Use Math.max and Math.min with the spread operator.

const arr = [1, 2, 3];
Math.max(...arr); // 3
Math.min(...arr); // 1