String in Dart/Flutter — Things you should know
String is an important data type in almost programming languages (if not all). Dart is not an exception. In this post, I will show you a several things that you may (or may not) know about String in Dart/Flutter.
1. String literals can be wrapped in single quotes or double quotes.
// Both are accepted in Dart
const singleQuoteString = 'Hello Coflutter';
const doubleQuoteString = "Hello Coflutter";👉 It is recommended that you make it consistently, choose one style and use it throughout your code.
2. If you use pedantic as your linter, single quotes is preferred.
// Warning with pedanticconst s1 = "Hello Coflutter"; // Warning: Only use double quotes for strings containing single quotes.
const s2 = "Hello. I'm Coflutter"; // OK
👉 You can find the rule here.
3. Use a backslash ( \ ) to escape special characters.
print("I'm Coflutter");
print("I\'m Coflutter");
print("I\'m \"Coflutter\"");
print('Path: C:\\Program Files\\Coflutter');// OutputI'm Coflutter
I'm Coflutter
I'm "Coflutter"
Path: C:\Program Files\Coflutter
4. “Raw” string (r before string) can be used to escape special character too.
// "Raw" stringprint(r'Path: C:\Program Files\Coflutter');
print(r'I have $100 USD');
// OutputPath: C:\Program Files\Coflutter
I have $100 USD
5. Triple quotes can be used to represent multiple lines string (instead of using “new line” character (\n)).
// Multiple lines stringprint(
'''This is a multiple line string,
created by Coflutter
'''
);
6. Override toString( ) method in your object to have beautiful output when print( ).
👉 Find details and example here.
7. String supports padding methods: paddingLeft( ) and paddingRight( ).
👉 Find details and example here.
8. String multiplication is supported in Dart. But the string must be placed before the multiply operator (Permutation does not work).
const fire = '🔥';
for (var i = 0; i <= 3; i++) {
// final output = i * fire;
// -> Error: The argument type 'String' can't be assigned to the parameter type 'num'.
final output = fire * i;
print(output);
}ABOUT NEXTFUNC
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