This is my second article about getting started

Dart data type

Graph LR A(data type)--> B(String type) A--> C(numeric type) A--> D(Boolean type) A--> E(List) A--> F(Map) A--> G(dynamic)
The data type Statement of the sample
Type String String a= “Hello “;

Var a =” Hello”
Numeric types Double c = 3.14;

Var c = 3.14;
The Boolean bool bool d = true;
List the List var e = [“1″,”2″,”3”];
The key value of the Map Ar person = {“name” :”张三”, “age”: 50};

var f = new Map();
Special dynamic a = ‘Dart’;

b = “JavaScript”;

Type String

In DART, both strings and characters are strings, not char. Declaration, plain declaration, multi-line character declaration, raw string declaration

// Common declaration
String str1 = 'Hello'; // Double quotation marks can also be ""// multi-line string, using three single quotation marks
String str2 = '''Hello Dart''';
// There are escape characters
String str3 = 'Hello \n Dard';
// Raw string, unescaped, preceded by r
str3 = r'Hello \n Dard';
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Numeric types

int a = 123; 
double b = 22.1; // Can be an integer or a floating-point type
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The Boolean

Boolean, true or false.

// Boolean values, only true and false
bool isTrue = true;
bool isFalse = false;print('Hello'.isNotEmpty);
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List the List

A list container for storing data. There is no array type.

var list1 = [1.2.3.4.'Dart'.true];// Declare the list
// The new keyword can also be used
list1 = new List(a);Copy the code

The key value of the Map

Map key-value pair type, development is also very common

Mapvar map1 = {'first': 'dart'.1: true.true: 2};// Declare and assign
map1 = new Map(a);// Can also be declared with the new keyword
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Special dynamic

Finally, we have our dynamic type, which can be assigned by any type. This is essentially the Java equivalent of Object. Dart is dynamic.

var a;
a = 10; //var This can be assigned to any type
a = 'Dart';
b = "JavaScript"; // Dynamic b = 20;
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