java - hashCode(): return of an integer after string -

i don't understand in code hashcode() methode: how can return integer if there string... add string next number doesn't maje string don't understand function equals, object o , o insteadof

  public imatriculation(int numeros, string word) {        this.numeros = numeros;         this.word = word;     }       public int hashcode() {         return this.word.hashcode() + this.numeros;     }     public boolean equals(object o) {         return   o instanceof imatriculation               && this.word.equals(((imatriculation) o).word)               && this.numeros == ((imatriculation) o).numeros;    } 

as pointed out hashcode returns int not string.

"o" object in java, anything, instanceof used check if object "o" imatriculation before going on , checking details of object.