for .. in is not supported

Rule arkts-no-for-in

Severity: error

ArkTS does not support the iteration over object contents by the for .. in loop. For objects, iteration over properties at runtime is considered redundant because object layout is known at compile time, and cannot change at runtime. For arrays, iterate with the regular for loop.

TypeScript

    let a: number[] = [1.0, 2.0, 3.0]
    for (let i in a) {
        console.log(a[i])
    }

ArkTS

    let a: number[] = [1.0, 2.0, 3.0]
    for (let i = 0; i < a.length; ++i) {
        console.log(a[i])
    }

See also

• Recipe 082: for-of is supported only for arrays, strings, sets, maps and classes derived from them (arkts-for-of-str-arr)