java入门第二季--第1章 类和对象--java中的构造方法

构造方法写法构造方法特征无参的构造方法/javaDemo2/src/com/imooc/Telphone.javapackage com.imooc;public class Telphone { public Telphone() { System.out.println(“无参的构造方法”); }}/javaDemo2/src/com/imooc/InitailTelphone.javapackage com.imooc;public class InitailTelphone { public static void main(String[] args) { // TODO Auto-generated method stub Telphone phone =new Telphone(); }}有参的构造方法/javaDemo2/src/com/imooc/Telphone.javapackage com.imooc;import com.sun.glass.ui.Screen;public class Telphone { float screen; float cpu; public Telphone() { System.out.println(“无参的构造方法”); } public Telphone(float newScreen,float newCpu) { screen = newScreen; cpu = newCpu; System.out.println(“有参的构造方法”); }}/javaDemo2/src/com/imooc/InitailTelphone.javapackage com.imooc;public class InitailTelphone { public static void main(String[] args) { // TODO Auto-generated method stub Telphone phone =new Telphone(); Telphone phone2 =new Telphone(5.0f,1.4f); }}构造方法给对象的属性一个合理的值/javaDemo2/src/com/imooc/Telphone.javapackage com.imooc;import com.sun.glass.ui.Screen;public class Telphone { float screen; float cpu; public Telphone() { System.out.println(“无参的构造方法”); } public Telphone(float newScreen,float newCpu) { if(newScreen <3.5f) { System.out.println(“你的参数有误”); screen = 3.5f; } screen = newScreen; cpu = newCpu; System.out.println(“有参的构造方法”); }}/javaDemo2/src/com/imooc/InitailTelphone.javapackage com.imooc;public class InitailTelphone { public static void main(String[] args) { // TODO Auto-generated method stub Telphone phone =new Telphone(); Telphone phone2 =new Telphone(1.5f,1.4f); }}效果