字符串转换
// String -> int
var one = int.parse('1');
assert(one == 1);
// String -> double
var onePointOne = double.parse('1.1');
assert(onePointOne == 1.1);
// int -> String
String oneAsString = 1.toString();
assert(oneAsString == '1');
// double -> String
String piAsString = 3.14159.toStringAsFixed(2);
assert(piAsString == '3.14');
字符串拼接
var s1 = 'String '
'concatenation'
" works even over line breaks.";
assert(s1 ==
'String concatenation works even over '
'line breaks.');
var s2 = 'The + operator ' + 'works, as well.';
assert(s2 == 'The + operator works, as well.');
把变量插入字符串
var s = 'string interpolation';
assert('Dart has $s, which is very handy.' ==
'Dart has string interpolation, ' +
'which is very handy.');
assert('That deserves all caps. ' +
'${s.toUpperCase()} is very handy!' ==
'That deserves all caps. ' +
'STRING INTERPOLATION is very handy!');
多行字符串
var s1 = '''
You can create
multi-line strings like this one.
''';
var s2 = """This is also a
multi-line string.""";
var s = r'In a raw string, not even \n gets special treatment.';