description

# startsWith abstract method

bool startsWith(

1. Pattern pattern, [
2. int index = 0

])

Whether this string starts with a match of `pattern`.

    const string = 'Dart is open source';
    print(string.startsWith('Dar')); // true
    print(string.startsWith(RegExp(r'[A-Z][a-z]'))); // true

If `index` is provided, this method checks if the substring starting at that index starts with a match of `pattern`:

    const string = 'Dart';
    print(string.startsWith('art', 0)); // false
    print(string.startsWith('art', 1)); // true
    print(string.startsWith(RegExp(r'\w{3}'), 2)); // false

`index` must not be negative or greater than length.

A RegExp containing '^' does not match if the `index` is greater than zero and the regexp is not multi-line. The pattern works on the string as a whole, and does not extract a substring starting at `index` first:

    const string = 'Dart';
    print(string.startsWith(RegExp(r'^art'), 1)); // false
    print(string.startsWith(RegExp(r'art'), 1)); // true

## Implementation

    bool startsWith(Pattern pattern, [int index = 0]);