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List<String> list = new ArrayList<String>();
list.add(“item”);
String item = list.get(0);
Set<String> set = new HashSet<String>();
set.add(“item”);
Map<String, Integer> map = new HashMap<String, Integer>();
map.put(“key”, 1);
int value = map.get(“key”);
List<String> list = new ArrayList<String>();
list.add("item");
String item = list.get(0);
Set<String> set = new HashSet<String>();
set.add("item");
Map<String, Integer> map = new HashMap<String, Integer>();
map.put("key", 1);
int value = map.get("key");
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List<String> list = ["item"];
String item = list[0];
Set<String> set = {“item”};
Map<String, Integer> map = {“key” : 1};
int value = map["key"];
List<String> list = ["item"];
String item = list[0];
Set<String> set = {"item"};
Map<String, Integer> map = {"key" : 1};
int value = map["key"];
2.×Ô¶¯×ÊÔ´¹ÜÀí
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BufferedReader br = new BufferedReader(new FileReader(path));
try {
return br.readLine();
} finally {
br.close();
}
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try {
return
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