Finds the first occurrence of a character in a string

The Java map interface provides an object that maps a key to a value, HashMap TreeMap

Method	Function
Put (K key, V value)	Adds a mapping relationship for the specified key, value to the collection
ContainsKey (Object key)	Returns true if the mapping relationship that contains the specified key is checked
Containsvalue (Object value)	This mapping maps one or more keys to the specified value values, returning True
Get (Object key)	Returns the value of the specified key, otherwise returns null
KeySet ()	Returns the set set formed by all key objects
VALUES ()	Returns the collection collection of all value objects

Algorithm title: Find the first occurrence of a character in a string.

1  PackageOffer ;2 3 ImportJava.util.HashMap;4 5  Public classFind_char {6 7      Public Static voidMain (string[] args) {8         //TODO auto-generated Method Stub9Get ("Abcdefacbwqewwwwewqew");Ten     } One  A      Public Static voidget (String s) { -Hashmap<string,integer> map=NewHashmap<string,integer>(); -         Char[] cs=S.tochararray (); the          for(inti=0;i<cs.length;i++){ -             if(Map.containskey (cs[i]+ "")) {//to see if a mapping relationship with the specified key value is included -Map.put (cs[i]+ "", (Map.get (cs[i]+ "") +1));//The Get function returns the value corresponding to the specified key key, otherwise returns null -             } +             Else{ -Map.put (cs[i]+ "", 1); +                                      A                 } at             } -          for(intj=0;j<cs.length;j++){ -             if(Map.get (cs[j]+ "") ==1) {//the Get () returns the value of the specified key value key; - System.out.println (Cs[j]); -                  Break; -                  in             } -         } to     } +}

Finds the first occurrence of a character in a string