for (Token tk: scanner.getTokens()) 等同于for(int i = 0; i < scanner.getTokens()){Token tk = scanner.getTokens.get(i);} Token:变量tk的类型 tk: 相当于以前的Token tk = scanner.getTokens.get(i); scanner.getTokens(): Token源集合assert out.equals(System.out);晕我还真没遇见过~~~
对于数组和所有实现了Iterable接口的类,都可以这样用int[] a = {1,2,3,4}; for(int i : a) System.out.println(i);List<String> list = ...; for(String s : list) System.out.println(s)
新特性
public class TestJdk {
public static void main(String args[]) {
String str = "a,b,c,c,c" ;
//jdk5.0新特性
for (String ch : str.split(",")) {
System.out.println(ch) ;
}
print(str.split(",")) ;
}
public static void print(String ...str) {
for(String ch:str) {
System.out.println(ch) ;
}
}
}
等同于for(int i = 0; i < scanner.getTokens()){Token tk = scanner.getTokens.get(i);}
Token:变量tk的类型
tk: 相当于以前的Token tk = scanner.getTokens.get(i);
scanner.getTokens(): Token源集合assert out.equals(System.out);晕我还真没遇见过~~~
for(int i : a) System.out.println(i);List<String> list = ...;
for(String s : list) System.out.println(s)