Question about java concurrenthashmap replace method -

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i have following code

public class test{  private static final string key = "key";  public static void main(string[] a){     concurrenthashmap<string,string > map = new concurrenthashmap<string,string>();     system.out.println(map.replace(key,"1"));     system.out.println(map.replace(key,"2")); }  }

the output null both times. isn't supposed 1 second time?

the doc says:

replace entry key if mapped value. acts as

if ((map.containskey(key))      return map.put(key, value);    else     return null;

hence no, first replace doesn't put.


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