如何在Java中调用我的void方法？

Question

this program works.. i tested it without using switch.. my only issue is not knowing how to invoke the whichtable(int number) method.

package switchmathtables;  
import javax.swing.JOptionPane;
public class MathTables {
public static void printAddition(int x){
    int i = 1; 
    while (x <= 12){
    System.out.print (0 + x + "   ");
    x = x + 1;
}
System.out.println ("");

}
public static void printSinTable(){
double x, y, z;    
System.out.print("Angle 30 degree ");
    x = 30 * Math.PI/180;
    System.out.println ("sin(" + x + ") is " + Math.asin(x));
     System.out.print("Angle 60 degree ");
    y = 30 * Math.PI/180;  
}
public static void printCosTable(){
double x, y, z;     
System.out.print("Angle 30 degree ");
    x = 30 * Math.PI/180;
    System.out.println ("cos(" + x + ") is " + Math.acos(x));
    System.out.print("Angle 60 degree ");
    y = 30 * Math.PI/180;
}
public static void printTanTable(){
 double x, y, z;  
 System.out.print("Angle 30 degree ");
    x = 30 * Math.PI/180;
    System.out.println("tan(" + x + ") is " + Math.atan(x));
    System.out.print("Angle 60 degree ");
    y = 30 * Math.PI/180;   
}



public static void printCommonLog(){
double x = 0.5;
while(x < 10) {
    System.out.println( x + "  " + Math.log(x) / Math.log(10));
    x = x + 0.05;
}

}

this is the void switch method i want to call from my main. I am not sure how too

public static void printAddition(){
int x = 1;
while (x <= 12){
    System.out.print (0 + x + "   ");
    x = x + 1;
}
System.out.println ("");
}
public static void whichtable(int number){

switch (number){
 case 1:
     printCommonLog();
     break;
 case 2:
     printAddition();
     break;
 case 3:
     printTanTable();
     break;        
 case 4:
     printCosTable();
     break;
 case 5:
     printSinTable();
     break;
 }  

This is my main and I want to call the whichtable(int number) method into it..

 } 
 public static void main(String[] args) {
 int number;
 String inputStr = JOptionPane.showInputDialog ("Type 1 for CommonLog table"
     + "Type 2 for Addition table"
     + "Type 3 for the tangent table"
     + "Type the 4 for the cosine table"
     + "Type the 5 for the sine");       
  }}

Answer 1

If you know that they typed in an integer on the input string you could say MathTables.whichtable(Integer.parseInt(inputStr)) in main and it would print out one of the tables.

If main is in the same class as MathTables then you would only need to use whichtable(Integer.parseInt(inputStr)) , but it's good programming practice to make a runnable class along with the class you're working with for testing and debugging.

Answer 2

Since you need to convert a String to a number from your dialog, you need to parse it.

int option = Integer.parseInt(inputStr); // Convert the String to an "int"
whichtable(option); // Call the void method!

Answer 3

In your inputStr you have the input of the user. You have to parse that to integer and then call your method. You can use

final Integer choice = Integer.parseInt(stringToParse);
whichtable(choice);

Answer 4

Use :

whichtable(Integer.parseInt(inputStr));

the whichtable method expects an Integer , so you must convert it.

Answer 5

you get a string with using JOptionPane.showInputDialog so when i type 3 inputStr will be "3"

you can parse it to integer and call your method

whichtable(String.valueOf(inputStr));