Strategy Pattern

Algorithm switching pattern
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The sample code is Compare two class instances A class that returns the comparison result as an int value Create with Strategy inheritance class

I haven't switched the algorithm The int value of the return value is expressed as an algorithm

Check with the following class structure

class	Explanation
interface Strategy	Define switching algorithm methods Method is sam.Compares two instances of class and returns the comparison result as an int value
compare.class	Implement Strategy
useStrategy.class	Used by user to execute switching algorithm
sam.class	Target class to be compared
user(Main.class)	Operation check

User Includes the meaning that other developers use this pattern

`interface_Strategy`


interface Strategy{int compare(sam s1,sam s2);}

`compare.class`


class compare implements Strategy{
  public int compare(sam s1,sam s2){
    if(s1.i <  s2.i){return 1;}else
    if(s1.i == s2.i){return 0;}else{
       return -1;
    }
  }
}

`useStrategy.class`


class useStrategy{
  Strategy strategy = null;
  useStrategy(Strategy st)  {this.strategy=st;}
  int compare(sam s1,sam s2){return strategy.compare(s1,s2);}
}

`sam.class`


class sam{
      String str;
      int i;
      sam(String str,int i){
          this.str = str;
          this.i   = i;
      }
}

`user(Main.class)`


public static void main(String[] args){
  sam sam1 = new sam("s1",3);
  sam sam2 = new sam("s2",2);
  compare     com = new compare();
  useStrategy us  = new useStrategy(com);
  System.out.println(us.compare(sam1,sam2));
}}