Create an array of cumulative sum

Replace each number with the running total up to it.

JavaScript Version 1.0.0 · MIT · .md

function accumulate(values) { let total = 0; return values.map(value => (total += value)); }

Input & expected output

[
  1,
  2,
  3,
  4
]

[
  1,
  3,
  6,
  10
]

The edge case

[]

[]

Know the limits

• Floating-point totals can drift; sum integer minor units for money.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Keep exploring

• Clone an array — Create a new array without copying the objects inside it.
• Remove duplicate values — Keep the first occurrence of each value, in its original order.
• Flatten a nested array — Turn a nested array into one sequence of values.