Range generator in JavaScript

A generator that yields numbers lazily, so an enormous range costs nothing.

function* range(start, stop, step = 1) {
  if (stop === undefined) {
    stop = start;
    start = 0;
  }
  for (let i = start; step > 0 ? i < stop : i > stop; i += step) {
    yield i;
  }
}

Keywords and builtins used here

• for
• function
• if
• let
• yield

The run, in numbers

Lines

9

Characters to type

171

Tokens

58

Three-star pace

85 tpm

At the three-star pace of 85 tokens a minute, this run takes about 41 seconds.

Type this snippet

Step 3 of 3 in Control flow, step 13 of 43 in Language basics.

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