Reports calls like "abc".substring(0, 1) that can be replaced with "abc"[0].

Obtaining the element by index makes your code simpler.

The quick-fix replaces the substring call with the indexing operator.

Example:


  fun foo() {
      "abc".substring(0, 1)
  }

After the quick-fix is applied:


  fun foo() {
      "abc"[0]
  }