Dart basis

First, create the environment IDEA

1, Dart plug-in installation

2. Select Dart SDK

3, create a new console project

 

 

 The main in the bin directory, really live for a long time to see.

Second, the basic data type

1, the string type

a, adding

String str1="123_456";
String str2="_789";
String str3=str1+str2; 
print(str1+str2);
//123_456_789

b, taken

String str1="123_456";
String str2=str1.substring(0,3);
print(str2);
//123

c, divided

List<String> v=str1.split('_');

d, dart no character type, such as

import 'dart:mirrors';

import 'package:dartstudy/dartstudy.dart' as dartstudy;
getTypeName(dynamic obj) {
  return reflect(obj).type.reflectedType.toString();
}
void main(List<String> arguments) {
  String str1="123_456";
  var a=str1[0];
  print(getTypeName(a));

  var b='1';
  print(getTypeName(b));

}
//输出 都是String

2, numerical type

var v=23.0;
print(getTypeName(v));
//double

var v=2;
print(getTypeName(v));
//int

int range below

 

 64-bit double precision

3, Mathematical Functions

import 'dart:mirrors';
import 'dart:math';
import 'package:dartstudy/dartstudy.dart' as dartstudy;
getTypeName(dynamic obj) {
  return reflect(obj).type.reflectedType.toString();
}
void main(List<String> arguments) {
  var v=23.5.round();
  print(v);

}
//24