'index' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.

[plantain-00]

Bug Report

🔎 Search Terms

implicitly has type 'any' 7022

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about _________

⏯ Playground Link

Playground link with relevant code

💻 Code

let children: string | A[] = []
while (typeof children !== 'string') {
    const index = children.length - 1
    children = children[index].children
}

interface A {
  children: A[] | string
}

🙁 Actual behavior

'index' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer

🙂 Expected behavior

No error here

[MartinJohns]

Duplicate of #43047. The type of index depends on the type of children, the type of children depends on the type of index (due to the reassignment).

Just add a type annotation.