Tips & Tricks

Programming

Use console.time() for Performance Measurement

Problem

Measuring code execution time requires manual Date.now() calculations.

Solution

Use console.time() and console.timeEnd() to measure execution time easily.

Benefit

Simple, accurate performance measurement without manual timestamp math.

Code Example Read tip

Math

Add Long Columns of Numbers Quickly

Problem

Adding long lists of numbers one at a time is slow and error-prone.

Solution

Look for pairs that sum to 10, group numbers that are easy to add (like 25+75=100).

Benefit

Speeds up mental addition by 50% by reducing the number of operations.

Example Read tip

Programming Popular

Use console.table() Instead of console.log()

Problem

Debugging arrays of objects with console.log() produces hard-to-read nested output that requires expanding each item.

Solution

Use console.table() to display arrays and objects in a clean, sortable table format in your browser DevTools.

Benefit

Instantly see all data in a structured table — sortable by column, easy to scan, no expanding needed.

Code Example Read tip

Math Popular

The Rule of 72 — Estimate Doubling Time

Problem

Calculating how long it takes for an investment to double at a given interest rate requires compound interest formulas.

Solution

Divide 72 by the annual interest rate to get the approximate number of years to double your money.

Benefit

Instant mental calculation for financial planning — no calculator or compound interest formula needed.

Example Read tip

Programming Popular

Name Booleans Like Yes/No Questions

Problem

Boolean variables named "active", "permission", or "valid" are ambiguous — is it a status, a check, or an action?

Solution

Prefix booleans with is, has, can, should, or was. They read like questions: isActive, hasPermission, canEdit.

Benefit

Code reads like English. "if (isActive && hasPermission)" is instantly understandable vs "if (active && permission)".

Code Example Read tip

Math Popular

Flip Percentages for Easier Calculation

Problem

Some percentage calculations like "8% of 50" are harder to compute mentally than their flipped equivalent.

Solution

X% of Y = Y% of X. Always flip to whichever is easier. 8% of 50 = 50% of 8 = 4.

Benefit

Turns difficult percentage problems into trivial ones — works every time because multiplication is commutative.

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Programming Popular

Never Hardcode Magic Numbers

Problem

Code like "if (status === 3)" or "timeout = 86400" is meaningless to anyone reading it — including your future self.

Solution

Replace magic numbers with named constants. The name explains the purpose, and changing the value only requires one edit.

Benefit

Self-documenting code, fewer bugs when values change, and easier code reviews.

Code Example Read tip

Math Popular

Square Numbers Ending in 5 Instantly

Problem

Squaring numbers like 35, 65, or 85 requires long multiplication that is slow and error-prone.

Solution

Take the tens digit, multiply it by (itself + 1), then append 25 at the end. Done.

Benefit

Square any number ending in 5 in under 3 seconds mentally — no pen, paper, or calculator needed.

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