Dart Strings
In Dart, strings are a fundamental data type used to represent sequences of characters. They are widely used for storing and manipulating text, and Dart provides a rich set of features and methods for working with strings. Below is an overview of strings in Dart, including how to create, manipulate, and format them.
String Basics
Creating Strings
Strings in Dart can be created using single quotes ('
), double quotes ("
), or triple quotes ('''
or """
). The choice of quotes depends on the use case, especially when dealing with quotes inside the string.
- Single and Double Quotes:
- Triple Quotes: Triple quotes are useful for multi-line strings or when the string contains both single and double quotes.
String Interpolation
Dart supports string interpolation, which allows you to embed expressions within string literals. This is done using the dollar sign ($
) followed by the variable name or the expression enclosed in curly braces ({}
).
Example:
String Methods
Dart provides a variety of built-in methods for manipulating strings. Here are some commonly used methods:
- Length: Returns the number of characters in the string.
- Concatenation: You can concatenate strings using the
+
operator or theStringBuffer
class for more efficient concatenation.
- Substrings: Extracts a portion of the string.
- Indexing: Access individual characters using their index (0-based).
- Trim: Removes leading and trailing whitespace.
- Replace: Replaces occurrences of a substring.
- Split: Splits the string into a list based on a delimiter.
String Comparison
Strings can be compared using equality operators (==
and !=
). Dart is case-sensitive when comparing strings.
Example:
Raw Strings
Dart allows the creation of raw strings using the r
prefix. Raw strings treat backslashes (\
) as literal characters and do not interpret escape sequences.
Example:
Conclusion
Strings in Dart are versatile and powerful, providing numerous methods and features for text manipulation and formatting. With support for string interpolation, multi-line strings, and a variety of built-in methods, Dart makes it easy to work with textual data. Understanding how to effectively use strings is essential for developing robust Dart applications, as they play a crucial role in user interaction, data representation, and application logic.