java - Getting A StackOverFlowError when making a basic calcualator -


i trying make calculator 4 functions , word based. when tried implement selecting of operations, stackoverflow error.

class calculator:

package us.plexproductions.main;  import java.util.scanner;  public class calculator {  public static int firstnum; public static int secondnum; public static int answer; public static int operation;  calculator c = new calculator(); static scanner s = new scanner(system.in);  static operations o = new operations();  public static void main(string[] args) {      prompt();     start(); }  public static void prompt() {     system.out.println("########################");     system.out.println("#calculator version 1.0#");     system.out.println("########################");     system.out.println("************************");     system.out.println("this calculator that\ncan add, subtract, multiply, , divide\n" +                        "multiple numbers @ once.");     system.out.println("------------------------");     system.out.println("start calculating entering number , then\nspelling out operation " +                        "want preform that\nnumber , type in number."); }  public static void start() {     system.out.println("------------------------");     system.out.println("enter first number: ");     firstnum = s.nextint();     system.out.println("------------------------");     system.out.println("which operation use?\naddition = 1, subtraction = 2, multiplication = 3, or division = 4?");     operation = s.nextint();     second();  }  public static void second() {     if (operation == 1) {         o.addition();     }     if (operation == 2) {         o.subtraction();     }     if (operation == 3) {         o.multiplication();     }     if (operation == 4) {         o.division();     } } }

class operations:

package us.plexproductions.main;  import java.util.scanner;  public class operations {  calculator c = new calculator(); scanner s2 = new scanner(system.in);  public void addition() {     system.out.println("addition selected.");     system.out.println("enter second number: ");     calculator.secondnum = s2.nextint(); }  public void subtraction() {  }  public void multiplication() {  }  public void division() {  } }

each instance of calculator creates new calculator() field c. these calculators, in turn, create more calculators, , on.

the stackoverflowerror occurs because sequence of calls calculator constructor never ends, filling available stack memory. doesn't appear need nested calculator, try removing it.


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