Skip to content

Calculator exercice #1

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 2 commits into
base: main
Choose a base branch
from
Open

Calculator exercice #1

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
87e99fa
exercise without exception handling
kanohapierre Jul 24, 2021
ef1ca1b
update
kanohapierre Jul 25, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
27 changes: 26 additions & 1 deletion src/main/java/com/serenitydojo/calculator/Calculator.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,31 @@

public class Calculator {
public int evaluate(String expression) {
return 0;

String operators[] = expression.replaceAll("\\s", "").split("[0-9]+");
String operands[] = expression.replaceAll("\\s", "").split("[*/+-]");

int runningTotal = Integer.parseInt(operands[0]);

for(int i=1; i<operands.length; i++) {
if(operators[i].equals("+")) {
runningTotal += Integer.parseInt(operands[i]);
}
else if(operators[i].equals("-")) {
runningTotal -= Integer.parseInt(operands[i]);
}
else if(operators[i].equals("*")) {
runningTotal *= Integer.parseInt(operands[i]);
}
else if(operators[i].equals("/")) {
runningTotal /= Integer.parseInt(operands[i]);
}
else
{
throw new IllegalMathsOperatorException("Unknown operator ");
}
}
return runningTotal;
}

}
7 changes: 7 additions & 0 deletions src/main/java/com/serenitydojo/calculator/IllegalMathsOperatorException.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
package com.serenitydojo.calculator;

public class IllegalMathsOperatorException extends RuntimeException {
public IllegalMathsOperatorException(String message) {
super(message);
}
}
69 changes: 34 additions & 35 deletions src/test/java/com/serenitydojo/calculator/WhenDoingMaths.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,5 @@
package com.serenitydojo.calculator;

import org.apache.commons.lang3.StringUtils;
import org.junit.Test;

import static org.assertj.core.api.Assertions.assertThat;
Expand All @@ -13,38 +12,38 @@ public void shouldReturnZeroForAnEmptyString() {
assertThat(calculator.evaluate("")).isEqualTo(0);
}

// @Test(expected = IllegalMathsOperatorException.class)
// public void shouldReportNonSupportedOperations() {
// calculator.evaluate("1 ^ 2");
// }
//
// @Test
// public void shouldReturnTheValueOfASingleNumber() {
// assertThat(calculator.evaluate("1")).isEqualTo(1);
// }
//
// @Test
// public void shouldAddTwoNumbers() {
// assertThat(calculator.evaluate("1 + 1")).isEqualTo(2);
// }
//
// @Test
// public void shouldAddThreeNumbers() {
// assertThat(calculator.evaluate("1 + 2 + 3")).isEqualTo(6);
// }
//
// @Test
// public void shouldAlsoSubtract() {
// assertThat(calculator.evaluate("10 - 6")).isEqualTo(4);
// }
//
// @Test
// public void shouldAddAndSubtract() {
// assertThat(calculator.evaluate("10 + 5 - 6")).isEqualTo(9);
// }
//
// @Test
// public void shouldMultiplyNumbers() {
// assertThat(calculator.evaluate("10 * 5")).isEqualTo(50);
// }
@Test(expected = IllegalMathsOperatorException.class)
public void shouldReportNonSupportedOperations() throws IllegalMathsOperatorException {
calculator.evaluate("1 ^ 2");
}

@Test
public void shouldReturnTheValueOfASingleNumber() {
assertThat(calculator.evaluate("1")).isEqualTo(1);
}

@Test
public void shouldAddTwoNumbers() {
assertThat(calculator.evaluate("1 + 1")).isEqualTo(2);
}

@Test
public void shouldAddThreeNumbers() {
assertThat(calculator.evaluate("1 + 2 + 3")).isEqualTo(6);
}

@Test
public void shouldAlsoSubtract() {
assertThat(calculator.evaluate("10 - 6")).isEqualTo(4);
}

@Test
public void shouldAddAndSubtract() {
assertThat(calculator.evaluate("10 + 5 - 6")).isEqualTo(9);
}

@Test
public void shouldMultiplyNumbers() {
assertThat(calculator.evaluate("10 * 5")).isEqualTo(50);
}
}