public class Colculter {
public double sum(double a,double b){
return a+b;
}
public double substract(double a,double b){
return a-b;
}
public double divide(double a,double b){
return a/b;
}
public double aulitply(double a,double b){
return a*b;
}
}
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import static org.junit.Assert.*;
public class colculterTest {
private Colculter mColculter;
@Before
public void setUp() throws Exception {
mColculter = new Colculter();
}
@After
public void tearDown() throws Exception {
}
@Test
public void sum() throws Exception {
assertEquals(8d, mColculter.sum(3d, 5d), 0);
}
@Test
public void substract() throws Exception {
assertEquals(1d, mColculter.substract(5d, 4d), 0);
}
@Test
public void divide() throws Exception {
assertEquals(4d, mColculter.divide(20d, 5d), 0);
}
@Test
public void aulitply() throws Exception {
assertEquals(20d, mColculter.divide(4d, 5d), 0);
}
}
![](https://images2015.cnblogs.com/blog/1118740/201703/1118740-20170317131233979-699735080.png)