public class ConstructorExample { private int i; ConstructorExample() { this(1); .... } ConstructorExample(int i) { .... this.i = i; .... } } 对于这种情况,Java只允许在ConstructorExample(int i)内调用超类的构造函数,也就是说,下面两种情形
publicclassEmployee{privateStringfirstName;privateStringlastName;publicEmployee(){//constructor 1}publicEmployee(StringfirstName){//constructor 2//statements}publicEmployee(StringfirstName,StringlastName){//constructor 3//statements}} If we define a non-default parameterized constructor in a class then JV...
ConstructorExample(inti) { ...this.i =i; ... } } 对于这种情况,Java只允许在ConstructorExample(int i)内调用超类的构造函数,也就是说,下面两种情形的代码编译是无法通过的: publicclassConstructorExample {privateinti; ConstructorExample() { super();this(1);//Error:Constructor call must be the firs...
packagecom.journaldev.constructor;publicclassData{privateStringname;privateintid;//no-args constructorpublicData(){this.name="Default Name";}//one parameter constructorpublicData(Stringn){this.name=n;}//two parameter constructorpublicData(Stringn,inti){this.name=n;this.id=i;}publicStringgetName()...
example 123 1. 调用构造函数 要调用构造函数,可以使用newInstance()方法。与创建对象实例类似,newInstance()方法会根据构造函数的参数类型,动态调用构造函数并返回对象实例。 示例代码: importjava.lang.reflect.Constructor;publicclassMyClass{publicMyClass(Stringarg1,intarg2){System.out.println(arg1+" "+arg2);...
}publicclassConstructorExample {publicstaticvoidmain(String... args) { Bar bar=newBar(); System.out.println(bar.getValue());//---(3)} }/** Output: 2 0 2*///Foo类构造函数的等价变换:Foo() { i= 1; i= 2; System.out.println(i);int x = getValue();// 在执行Foo的构造函数的...
Example 2: Accessing Members classCar{ String carName; String carType;// assign values using constructorpublicCar(String name, String type){this.carName = name;this.carType = type; }// private methodprivateStringgetCarName(){returnthis.carName; ...
publicclassReflectionExample{ publicstaticvoidmain(String[]args)throwsException{ // 获取 Class 对象 Class<?>clazz=Person.class; // 创建对象 Constructor<?>constructor=clazz.getConstructor(String.class,int.class); Objectperson=constructor.newInstance("John",30); ...
public class ConstructorExample { public static void main(String... args) { Bar bar = new Bar(); System.out.println(bar.getValue()); } } 输出: 2 0 2 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. ...
For example: public java.util.Hashtable(int,float) The only possible modifiers for constructors are the access modifiers public, protected or private. Only one of these may appear, or none if the constructor has default (package) access. Overrides: toString in class Object Returns: a ...