Question

JAVA

Write a program which will receive three pieces of data from the user: two floating point numbers, and a single character +, -, *, or /. Perform input validation on the character.

Your code then will send these three pieces of data to a method which will calculate and output the results based on the user's entries. For example, if the user entered: "12.1, 23.2, +" the output would be "12.1 + 23.2 = 35.3."

STRONG HINT: in a switch statement, a character can be evaluated just as easily as an integer. You can use "case '+': stmt; break;" and will want to use that format.

Format your output exactly as shown below, or improve on it:

Building PQ6.java and running PQ6
        > This program will ask you for two numbers and an
        > operator (such as +, -) and generate the results.
        > Enter two numbers separated by a space > 23 15
        > Enter the operator you want (+, -, *, /) > /
        > 23.00 / 15.00 = 1.53
        > Another problem? > y
        > Enter two numbers separated by a space > 45.6 87.9
        > Enter the operator you want (+, -, *, /) > *
        > 45.60 * 87.90 = 4008.24
        > Another problem? > u
        > ERROR: Y/N only > n

Answer 1

code:

import java.io.*;
import java.util.*;
class Chegg
{
public static void oper(String s1,String s2,char op)
{
double f1,f2,fres;
String res;
f1=Float.parseFloat(s1);
f2=Float.parseFloat(s2);//converting strings into float values
switch(op)//switch to check the operation
{
case '+':   fres=f1+f2;
   res=String.valueOf(fres);//converting the result into string
   System.out.println(f1+""+op+""+f2+"="+res);//printing result
   break;
case '-':   fres=f1-f2;
   res=String.valueOf(fres);
   System.out.println(f1+""+op+""+f2+"="+res);
   break;
case '*':    fres=f1*f2;
   res=String.valueOf(fres);
   System.out.println(f1+""+op+""+f2+"="+res);
   break;
case '/':    fres=f1/f2;
   res=String.valueOf(fres);
   System.out.println(f1+""+op+""+f2+"="+res);
   break;
default:System.out.println("Invalid");
}
}
public static void main(String args[])
{
String s1,s2,res,ap;//declaration of variables
char op;
int x=1;
Scanner sc=new Scanner(System.in);//Scanner object for reading input
while(x!=0)//until no is entered
{
System.out.print("Enter two numbers seperated by space>");
s1=sc.next();//reading float values as strings
s2=sc.next();
System.out.print("Enter the operator you want (+,-,*,/)>");
op=sc.next().charAt(0);//reading operator
oper(s1,s2,op);//method is called
System.out.print("Another problem?>");//asking for another operation
while(true)//checking until y or n is entered
{
ap=sc.next();
if(ap.compareTo("y")==0){
x=1;
break;
}
else if(ap.compareTo("n")==0){
x=0;
break;
}
else
System.out.print("Error Y/N only>");
}
}
}
}

code output:

Select Command Prompt C:Users\deeks \Desktop>javac HomeworkLib.java C:\Users\deeks\Desktop>java Chegg Enter two numbers seperated by space>31 22 Enter the operator you want (+, - ,*,/)>+ 31.8+22.8-53.0 Another problem?>y Enter two numbers seperated by space>31 22 Enter the operator you want (+,- ,*,/)>- 31.8-22.0-9. Another problem?>y Enter the operator you want (+,- ,*,/)> 31.8 22.e-682.e Another problem?>u Error Y/N only>n C:\Users\deeks \Desktop> ENG 10:39 ? s AIN ^ di) iN 12-04-2019