public class Flower {
private int petalCount = 0;
private String s = new String("null");
Flower(int petals) {
petalCount = petals;
System.out.println(
"Constructor w/ int arg only, petalCount= "
+ petalCount);
}
Flower(String ss) {
System.out.println(
"Constructor w/ String arg only, s=" + ss);
s = ss;
}
Flower(String s, int petals) {
this(petals);
//! this(s); // Can't call two!
this.s = s; // Another use of "this"
System.out.println("String & int args");
}
Flower() {
this("hi", 47);
System.out.println(
"default constructor (no args)");
}
void print() {
//! this(11); // Not inside non-constructor!
System.out.println(
"petalCount = " + petalCount + " s = "+ s);
}
public static void main(String[] args) {
Flower x = new Flower();
x.print();
}
}
我有几点不太明白.代码里的S在流程里的内容是"hi"而一些构造函数里的this.s怎么就会是null了?希望高手能帮我分析一下this("hi", 47)和Flower(String s, int petals)会产生什么样的影响?还有就是private String s = new String("null");又改变了什么?谢谢!
private int petalCount = 0;
private String s = new String("null");
Flower(int petals) {
petalCount = petals;
System.out.println(
"Constructor w/ int arg only, petalCount= "
+ petalCount);
}
Flower(String ss) {
System.out.println(
"Constructor w/ String arg only, s=" + ss);
s = ss;
}
Flower(String s, int petals) {
this(petals);
//! this(s); // Can't call two!
this.s = s; // Another use of "this"
System.out.println("String & int args");
}
Flower() {
this("hi", 47);
System.out.println(
"default constructor (no args)");
}
void print() {
//! this(11); // Not inside non-constructor!
System.out.println(
"petalCount = " + petalCount + " s = "+ s);
}
public static void main(String[] args) {
Flower x = new Flower();
x.print();
}
}
我有几点不太明白.代码里的S在流程里的内容是"hi"而一些构造函数里的this.s怎么就会是null了?希望高手能帮我分析一下this("hi", 47)和Flower(String s, int petals)会产生什么样的影响?还有就是private String s = new String("null");又改变了什么?谢谢!
解决方案 »
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