description

# indexOf method Null safety

int indexOf (

1. Object? element,
2. [int start = 0]

)
override

Returns the first index of `element` in this list.

Searches the list from index `start` to the end of the list. The first time an object `o` is encountered so that `o == element`, the index of `o` is returned.

    List<String> notes = ['do', 're', 'mi', 're'];
    notes.indexOf('re');    // 1
    notes.indexOf('re', 2); // 3

Returns -1 if `element` is not found.

    notes.indexOf('fa');    // -1

## Implementation

    int indexOf(Object? element, [int start = 0]) {
      if (start < 0) start = 0;
      for (int i = start; i < this.length; i++) {
        if (this[i] == element) return i;
      }
      return -1;
    }