Tips & Tricks

Programming

Use Array.from() to Convert Iterables

Problem

Converting NodeLists, Sets, or strings to arrays requires complex manual conversion.

Solution

Use Array.from() to convert any iterable into an array with optional mapping.

Benefit

Universal conversion solution that works with all iterable types.

Code Example Read tip

Math

Day of Week Algorithm (Mental Calendar)

Problem

Figuring out what day of the week a date falls on requires a calendar.

Solution

Use Zeller's congruence simplified: Learn anchor days for each month and count forward/backward.

Benefit

Impress others by calculating any date's day of week mentally.

Example Read tip

Programming Popular

Use Short-Circuit Evaluation

Problem

Conditional execution often requires verbose if statements for simple cases.

Solution

Use && for conditional execution and || for fallback values in one line.

Benefit

Reduces simple conditionals from 5 lines to 1 line.

Code Example Read tip

Math

Compound Interest Rule of 72

Problem

Calculating how long it takes for investment to double requires complex formulas.

Solution

Divide 72 by the interest rate to get approximate years to double.

Benefit

Quick investment doubling time calculation without formulas or calculators.

Example Read tip

Programming

Use JSON.parse() with Reviver Function

Problem

Parsing JSON with dates or special types requires manual post-processing.

Solution

Use the reviver parameter in JSON.parse() to transform values during parsing.

Benefit

Automates type conversion and eliminates separate transformation loops.

Code Example Read tip

Math

Estimate Cube Roots

Problem

Finding cube roots mentally is extremely difficult.

Solution

Memorize cubes 1-10, then find which two cubes the number falls between.

Benefit

Estimate cube roots within ±0.5 by knowing 10 reference points.

Example Read tip

Programming Popular

Use Object Shorthand Properties

Problem

Creating objects from variables requires repetitive key-value pairs.

Solution

Use ES6 shorthand to omit the value when key and variable name are the same.

Benefit

Reduces object creation code by 50% and improves readability.

Code Example Read tip

Math Popular

Percentage Increase/Decrease Formula

Problem

Calculating percentage change between two values is confusing and error-prone.

Solution

((New - Old) / Old) × 100. Positive = increase, negative = decrease.

Benefit

Universal formula for all percentage change calculations.

Example Read tip