Question

java数组使用iterate求和的问题!

import java.util.*;

class MyFrist1{
public static void main(String[] args){
Scanner scanner = new Scanner(System.in);
int[] myArray = new int[10];
System.out.println("Please type ten integers");
for(int i = 0; i < 10; i++){
myArray.add(scanner.nextLine());
}

Iterator<Integer> myIterator = myArray.iterator();

while(myIterator.hasNext()){
int sum = myIterator.next();
sum = sum + myIterator.next();
System.out.println(sum);
}
}
}
目的是想建立一个包含10ints类型的Array,然后从键盘里打10个int类型的字符放入Array,最后通过Iterate方式计算出总和。帮我看看代码哪里错了。谢谢！

Answer 1

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Scanner;

public class MyFrist1 {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);

List<Integer> list =new ArrayList<Integer>();

System.out.println("Please type ten integers");

for (int i = 0; i < 10; i++) {
list.add(scanner.nextInt());
}

Iterator<Integer> myIterator = list.iterator();

int sum = 0;
while (myIterator.hasNext()) {
int number = myIterator.next();
sum = sum + number;
}

System.out.println(sum);

}
}

首先，数组没有iterator,看你的代码应该用List<Integer>为佳

其次求和的时候sum应该在for循环外面，作用域范围错。

Answer 2

import java.util.*;

class StringIndex {
public static void main(String[] args){
Scanner scanner = new Scanner(System.in);
ArrayList<Integer> myArray = new ArrayList<Integer>();
int tempNum;
int sum ;//变量的声明最好不要放到循环中
System.out.println("Please type ten integers");
for(int i = 0; i < 10; i++){
tempNum= scanner.nextInt();
myArray.add(tempNum);
}

Iterator<Integer> myIterator = myArray.iterator();

while(myIterator.hasNext()){
sum= myIterator.next();
sum = sum + myIterator.next();
System.out.println(sum);
}
}
}

首先：不是任何的容器都能有iterator方法，必须要有一个实现Iterable接口的内部类，然后写了iterator方法 才能用