insert method
Inserts the string str
at the specified index
within the original string.
Throws RangeError if index
is out of bounds.
Example:
print('Hello World'.insert(6, 'Beautiful ')); // Output: 'Hello Beautiful World'
Implementation
String insert(int index, String str) {
if (index < 0 || index > length) {
throw RangeError('Index out of bounds');
}
return '${substring(0, index)}$str${substring(index)}';
}