dart 基本数据类型

基本数据类型

1. String 
2. Number
 * int
 * double
3. Boolean
4. List
5. Map

变量/对象的定义方式

1. String字符串

String str = "str";

2. int整型

int num = 123;

3. double浮点数

double num = 1.23;

4. bool布尔值

bool b = true;

5. list数组

var list = ["123", "321"]
var list = new List();
//添加泛型约束
var list = new List<String>();

6. map集合

var person = new Map();
person["name"] = "张三";
person["age"] = 22;
person["hobby"] = ["写代码", "不写文档"];

var person = {
    "name": "张三",
    "age": 22,
    "hobby": ["写代码", "不写文档"]
}; 

7. 使用var会自动推断数据类型

var str = "str";
var num = 123;

判断变量的数据类型

​ is关键字

var str = "123";
if (str is String) {
    print("字符串");
}else if (str is int){
    print("整型");
}