java - How can I change my program to allow user input to take the time? -

im struggling on project set myself. want user able input time, needs legal (i.e if time 9:15 , add 4 hours, must 01:15 please help!

package time;  public class newtime {      int hh, mm;      public newtime(int hh, int mm) {         if (hh > 0 && hh < 24 && mm > 0 && mm < 60) {              this.hh = hh;             this.mm = mm;          }     }      public void addtime(int hh, int mm) {         if (mm + this.mm > 59) {             this.hh += mm / 60;         }          this.hh += hh;         this.mm += mm;     } } 

your problem lies here:

public void addtime(int hh, int mm) {     if (mm + this.mm > 59) {         this.hh += mm / 60;     }      this.hh += hh; //<--source of problem     this.mm += mm; } 

you need check after addition whether hh variable more 12. if more 12 deduct 12. corrected format be:

public void addtime(int hh, int mm) {     this.hh += hh;     this.mm += mm;     this.hh += this.mm / 60;     this.mm = this.mm % 60; //this removes problem mm may 59 , this.mm 2      this.hh = this.hh % 12; //this solves problem of hour not getting on 12. } 

here instead of checking whether sum of this.mm , mm greater 59. add mm this.mm , add integer division result of this.mm / 60 hh. set remainder of integer division this.mm. repeat same thing hh store remainder of integer division of this.hh , 12 give output in 12 hour format.

this should take care of problem.