Dart Strings

In this chapter, we will learn about String data types and the properties and methods of Strings that are available in dart.

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Dart Strings

String refers to the collection of characters. For example,

String name = ‘Phil’;

In dart, strings are enclosed in either single quotes or double quotes. The keyword String is used to represent string value.

For example,

void main() {
String name1 = ‘Phil’;
String name2 = “Lauren”;
print(name1);
print(name2);
}

Output

Phil
Lauren

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Accessing Variables

We can use the quotes to access the variables and the strings using the dollar sign $ followed by the curly braces { }. For example,

void main() {
int age = 22;
String name = "Sam";
print("${name} is ${age} years old.");
}

Output

Sam is 22 years old.

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String Properties

Dart also provides various properties and methods that make the life of a programmer easier.

Some of the String properties are:

Property	Description
length	Returns the length of the string
isEmpty	Returns true if the string is empty
codeUnits	Returns an unmodified list of the UTF-16 code units of this string

String Properties Examples

void main() {
String name1 = "";
String name2 = "Phil";

print(name1.isEmpty);
print(name2.length);
print(name2.codeUnits);
}

Output

true
4
[80, 104, 105, 108]

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String Methods

Some of the useful String methods are:

Methods	Description
toUpperCase()	Converts all character to uppercase
toLowerCase()	Converts all character to lowercase
compareTo()	Compares one string from another
trim()	Removes all whitespace from leading and trailing spaces.
split()	Splits the string at matches of the specified delimiter and returns the list of the substring.
toString()	Returns the string representation of the given object
subString()	Returns the substring from start index, inclusive to end index
codeUnitAt()	Returns the 16-bits code unit at the given index
replaceAll()	Replaces all substring that matches the specified pattern with a given string

String Method Examples

void main() {
String name1 = "Phil";
String name2 = "   Hello World!     ";
  
print(name1.toUpperCase());
print(name1.toLowerCase());
print(name1.compareTo('Phil'));
print(name2.trim());
print(name1.substring(2,4));
print(name1.replaceAll('il','oebe'));
print(name1.split(''));
}

Output

PHIL
phil
0
Hello World!
il
Phoebe
[P, h, i, l]

In next chapter, We will learn about Dart Numbers.