从JDK1.5开始，Java支持个数可变的形参，类似：
public class ParamDemo {
public static void main(String[] args) {
String basketball = "篮球";
String football = "足球";
showSports(basketball, football);
}
public static void showSports(String... sports) {
for (String sport : sports) {
System.out.println(sport);
}
}
}
其实个数可变形参的本质就是一位数组，但是如果上面的例子采用一位数组的话，写起来要更加麻烦点。
public class ParamDemo {
public static void main(String[] args) {
String basketball = "篮球";
String football = "足球";
showSports(basketball, football);
showSportsByArray(new String[] { basketball, football });
}
public static void showSports(String... sports) {
for (String sport : sports) {
System.out.println(sport);
}
}
public static void showSportsByArray(String[] sports) {
for (String sport : sports) {
System.out.println(sport);
}
}
}
由于个数可变的形参数量不确定，所以只能放到形参列表的最后。而数组形式的参数是可以放到形参列表任意位置的。
3.2 个数可变形参本质是数组，所以不能算重载看下面的例子：
public class ParamDemo {
public static void main(String[] args) {
String basketball = "篮球";
String football = "足球";
showSports(basketball, football);
showSportsByArray(new String[] { basketball, football });
}
public static void showSports(String... sports) {
for (String sport : sports) {
System.out.println(sport);
}
}
public static void showSports(String[] sports) {
for (String sport : sports) {
System.out.println(sport);
}
}
}
编译就报错了，如下，说明啥？String...这样的形参其实还是编译为String[]运作的，所以不算重载。
Duplicate method showSports(String[]) in type ParamDemo ParamDemo.java
