Java Reference
In-Depth Information
38
if
(Character.isDigit(input.charAt(start)))
39 {
40 end = start +
1
;
41
while
(end < input.length()
42 &&
Character.isDigit(input.charAt(end)))
43 end++;
44 }
45
else
46 end = start +
1
;
47
return
r;
48 }
49
50
private
String input;
51
private int
start;
52
private int
end;
53 }
616
617
ch13/expr/ExpressionCalculator.java
1
import
java.util.Scanner;
2
3 /**
4
This program calculates the value of an expression
5
consisting of numbers, arithmetic
operators, and parentheses.
6 */
7
public class
ExpressionCalculator
8 {
9
public static void
main(String[] args)
10 {
11 Scanner in =
new
Scanner(System.in);
12 System.out.print(
"Enter an expression:
"
);
13 String input = in.nextLine();
14 Evaluator e =
new
Evaluator(input);
15
int
value = e.getExpressionValue();
16 System.out.println(input +
"="
+ value);
17 }
18 }
