1、Flutter的数据基本类型
- Dart语言里一切皆为对象，所以如果没有将变初始化,那么它的默认值为null
- Number(int、doubkle)
- String
- Boolean(bool)
- List
- Map
2、测试代码
void testData() { //Number包含了int和double int a = 4; int b = 8; print(a + b); int a1; if (a == null) { print('a == null'); } else { print('a != null'); } if (a1 == null) { print('a1 == null'); } else { print('a1 != null'); } double c = 5.9; double d = 6.4; print(c + d); //String类型 var chen = 'chen'; var yu = 'yu'; var name = chen + yu; print(name); var hello = ''' hello word public static void main1 '''; print(hello); var word = """ hello word public stati void main2 """; print(word); //Boolean类型 bool isSelect = false; if (isSelect) { print('isSelect is true'); } else { print('isSelect is false'); } //List类型 var list = []; list.add(1); list.add(2); print(list); print('size is ${list.length}'); list.removeAt(0); print(list); print('size is ${list.length}'); //Map类型 var week = {'one':'test1', 'two':'test2'}; print(week); print('week length is ${week.length}'); week.putIfAbsent('three', () => 'test3'); print(week); print('week length is ${week.length}'); }
3、运行结果
I/flutter (24359): 12 I/flutter (24359): a != null I/flutter (24359): a1 == null I/flutter (24359): 12.3 I/flutter (24359): chenyu I/flutter (24359): hello word I/flutter (24359): public static void main1 I/flutter (24359): I/flutter (24359): hello word I/flutter (24359): public stati void main2 I/flutter (24359): I/flutter (24359): isSelect is false I/flutter (24359): [1, 2] I/flutter (24359): size is 2 I/flutter (24359): [2] I/flutter (24359): size is 1 I/flutter (24359): {one: test1, two: test2} I/flutter (24359): week length is 2 I/flutter (24359): {one: test1, two: test2, three: test3} I/flutter (24359): week length is 3
