Floating Point

Floating point representations are not true repsentation of real numbers.

// 0.1 + 0.2 != 0.3
console.log(0.1 + 0.2); // 0.30000000000000004

When you write 0.3 in JS, it is stored as:

0.299999999999999988897769753748434595763683319091796875

Which is rounded/trimmed as 0.3 when printed.

When you add 0.1 and 0.2, here is what happens:

0.1 
// 0.1000000000000000055511151231257827021181583404541015625

0.2
// 0.200000000000000011102230246251565404236316680908203125

0.1 + 0.2 
// 0.3000000000000000444089209850062616169452667236328125

The "error" caused by adding the two floating point representation of 0.1 and 0.2 pushed the result above the error threshold of 0.3.

Think of it like a currency conversion:

• There is never a clean conversion between currencies.
• When you convert US dollar to a Euro,

Faster null check with integer inputs

With integer inputs, checking for null or zero value faster.

// commonly used approach
if(x != 0) { 
  // ...
} 

// faster approach using omit operation
if(x) {
  // 0 is False
  // other is True 
}

Coerce to zero on integer expectation

Coercing non-zero falsy values to zero with OR.

This works because the OR operator returns the value of the second operand when the first operand is falsy.

integerExpectation = nonZeroFalsyValue || 0;