1# The comma operator ``,`` is supported only in ``for`` loops 2 3Rule ``arkts-no-comma-outside-loops`` 4 5**Severity: error** 6 7ArkTS supports the comma operator ``,`` only in ``for`` loops. Otherwise, 8it is useless as it makes the execution order harder to understand. 9 10 11## TypeScript 12 13 14``` 15 16 for (let i = 0, j = 0; i < 10; ++i, j += 2) { 17 console.log(i) 18 console.log(j) 19 } 20 21 let x = 0 22 x = (++x, x++) // 1 23 24``` 25 26## ArkTS 27 28 29``` 30 31 for (let i = 0, j = 0; i < 10; ++i, j += 2) { 32 console.log(i) 33 console.log(j) 34 } 35 36 // Use explicit execution order instead of the comma operator: 37 let x = 0 38 ++x 39 x = x++ 40 41``` 42 43 44