30-seconds-of-code/snippets/sum.md

sum

Returns the sum of an of two or more numbers/arrays.

Use Array.reduce() to add each value to an accumulator, initialized with a value of 0.

const sum = (...arr) => [].concat(...arr).reduce((acc, val) => acc + val, 0);

sum([1, 2, 3, 4]); // 10