Tips & Tricks

Programming

Use Array.reduce() for Powerful Transformations

Problem

Complex array transformations require multiple passes and intermediate variables.

Solution

Use Array.reduce() to transform arrays into any shape (sum, object, grouped data).

Benefit

Single-pass solution that handles complex transformations efficiently.

Code Example Read tip

Math

Convert Celsius to Fahrenheit Quickly

Problem

The exact formula (C × 9/5) + 32 is difficult to calculate mentally.

Solution

Double the Celsius, subtract 10%, then add 32.

Benefit

Estimates Fahrenheit within ±1 degree using simple mental math.

Example Read tip

Programming

Use console.table() for Debugging

Problem

Debugging arrays of objects with console.log() makes data hard to read and compare.

Solution

Use console.table() to display arrays and objects in a formatted table.

Benefit

Makes debugging 10x faster with clear, sortable table visualization.

Code Example Read tip

Math

Check Multiplication with 9s Trick

Problem

Verifying multiplication results requires recalculating the entire problem.

Solution

Use casting out nines: Sum digits of each number repeatedly until single digit, then verify.

Benefit

Quick verification method that catches 90% of calculation errors.

Example Read tip

Programming

Use Nullish Coalescing for Default Values

Problem

Using || for defaults treats 0 and false as falsy, causing unexpected behavior.

Solution

Use ?? (nullish coalescing) which only triggers for null/undefined, not 0/false.

Benefit

Prevents bugs when working with 0, false, or empty strings as valid values.

Code Example Read tip

Math

Subtract from 1000 Quickly

Problem

Subtracting from 1000 with borrowing is error-prone.

Solution

Subtract each digit from 9, except the last digit which you subtract from 10.

Benefit

No borrowing needed, eliminates most common subtraction errors.

Example Read tip

Programming Popular

Use Arrow Functions for Shorter Callbacks

Problem

Traditional function syntax in callbacks adds unnecessary verbosity.

Solution

Use arrow functions (=>) for concise callback syntax with implicit returns.

Benefit

Reduces callback code by 40% and automatically binds this context.

Code Example Read tip

Math

Multiply by 15 Shortcut

Problem

Multiplying by 15 requires multiple steps with traditional methods.

Solution

Multiply by 10, then add half of that result.

Benefit

Reduces complex multiplication to simple addition.

Example Read tip