java 在迭代器上显示 Map 的内容
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Displaying the contents of a Map over iterator
提问by Sunmit Girme
I am trying to display the mapi have created using the Iterator.
The code I am using is:
我正在尝试显示map我使用迭代器创建的。我正在使用的代码是：
private void displayMap(Map<String, MyGroup> dg) {
Iterator it = dg.entrySet().iterator(); //line 1
while (it.hasNext()) {
Map.Entry pair = (Map.Entry)it.next();
System.out.println(pair.getKey() + " = " + pair.getValue());
it.remove();
}
}
Class MyGroup and it has two fields in it, named idand name.
I want to display these two values against the pair.getValue().
The problem here is Line 1 never gets executed nor it throws any exception.
类 MyGroup 并且它有两个字段，namedid和name. 我想针对pair.getValue(). 这里的问题是第 1 行永远不会被执行，也不会抛出任何异常。
Please Help.
请帮忙。
PS: I have tried every method on this link.
PS：我已经尝试了此链接上的所有方法。
回答by Chandra Sekhar
Map<String, MyGroup> map = new HashMap<String, MyGroup>();
for (Map.Entry<String, MyGroup> entry : map.entrySet()) {
System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());
}
using iterator
使用迭代器
Map<String, MyGroup> map = new HashMap<String, MyGroup>();
Iterator<Map.Entry<String, MyGroup>> entries = map.entrySet().iterator();
while (entries.hasNext()) {
Map.Entry<String, MyGroup> entry = entries.next();
System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());
}
For more iteration information see this link
有关更多迭代信息，请参阅此链接
