Errors when trying to compile java file

Question

I get several errors when trying to compile with java. This is my first post on stack overflow, so please point out mistakes in my post.

The code is some test code i made for a practical.

The following is my code:

public class MiscUtilsTest
{

    public static void main(String[] args)
    {
    testMax();
    testCalcGrade();
    testRoomArea();
    }

    public static void testMax()
    {
    int num, num2, num3;

    num = MiscUtils.max(9, 2);
    assert 9 == num;

    num2 = MiscUtils.max(6, 1);
    assert 6 == num2;

    num3 = MiscUtils.max(7, 7);
    assert 7 == num3;

    }

    public static void testCalcGrade()
    {
    int grade1, grade2, grade3, grade4, grade5, grade6, grade7, grade8, grade9;

    grade1 = MiscUtils.calcGrade(2);
    assert "F".equals(grade1);

    grade2 = MiscUtils.calcGrade(15);
    assert "F".equals(grade2);

    grade3 = MiscUtils.calcGrade(28);
    assert "F".equals(grade3);

    grade4 = MiscUtils.calcGrade(33);
    assert "F".equals(grade4);

    grade5 = MiscUtils.calcGrade(40);
    assert "F".equals(grade5);

    grade6 = MiscUtils.calcGrade(49);
    assert "F".equals(grade6);

    grade7 = MiscUtils.calcGrade(82);
    assert "8".equals(grade7);

    grade8 = MiscUtils.calcGrade(125);
    assert "".equals(grade8);

    grade9 = MiscUtils.calcGrade(-12);
    assert "".equals(grade9);

    }

    public static void testRoomArea()
    {
    int test, test2, test3;

    test2 = MiscUtils.roomArea(-10, 5);
    assert 0 == test;

    test2 = MiscUtils.roomArea(6, 2);
    assert 0 == test2;

    test3 = MiscUtils.roomArea(5, 10);
    assert 50 == test3;

    }
}

---

The following is the errors i get while while compiling -

MiscUtilsTest.java:45: error: cannot find symbol
MiscUtilsTest.java:30: error: incompatible types: String cannot be converted to int
    grade1 = MiscUtils.calcGrade(2);
                                ^
MiscUtilsTest.java:33: error: incompatible types: String cannot be converted to int
    grade2 = MiscUtils.calcGrade(15);
                                ^
MiscUtilsTest.java:36: error: incompatible types: String cannot be converted to int
    grade3 = MiscUtils.calcGrade(28);
                                ^
MiscUtilsTest.java:39: error: incompatible types: String cannot be converted to int
    grade4 = MiscUtils.calcGrade(33);
                                ^
MiscUtilsTest.java:42: error: incompatible types: String cannot be converted to int
    grade5 = MiscUtils.calcGrade(40);
                                ^
MiscUtilsTest.java:45: error: incompatible types: String cannot be converted to int
    grade6 = MiscUtils.calcGrade(49);
                                ^
MiscUtilsTest.java:48: error: incompatible types: String cannot be converted to int
    grade7 = MiscUtils.calcGrade(82);
                                ^
MiscUtilsTest.java:51: error: incompatible types: String cannot be converted to int
    grade8 = MiscUtils.calcGrade(125);
                                ^
MiscUtilsTest.java:54: error: incompatible types: String cannot be converted to int
    grade9 = MiscUtils.calcGrade(-12);
                                ^
9 errors

For those asking about the class file, Code from MiscUtils.class

import java.io.PrintStream;
import java.io.PrintStream;

public class MiscUtils
{
static
{
    System.out.println("[FYI: You are testing the *working* version of MiscUtils. Your test harness *should not* find any problems.]");
 }

public static int max(int paramInt1, int paramInt2)
{
    int i = paramInt1;
    if (paramInt2 > paramInt1) {
    i = paramInt2;
    }
    return i;
}

public static String calcGrade(int paramInt)
{
    String str = "";
    if ((paramInt >= 0) && (paramInt <= 100)) {
    if (paramInt >= 50) {
    str = str + paramInt / 10;
    } else {
    str = "F";
    }
    }
    return str;
}

public static int roomArea(int paramInt1, int paramInt2)
{
    int i = 0;
    if ((paramInt1 > 0) && (paramInt2 >= paramInt1) && (paramInt2 <= 3 * paramInt1)) {
    i = paramInt1 * paramInt2;
 }
    return i;
}
}

Answer 1

我认为您MiscUtils类缺少编译器错误中显示的方法。

Answer 2

You have not imported the class MiscUtils. Thus its giving error.

Use import syntax before class MiscUtilsTest.

import MiscUtils.*;

Answer 3

change:

 int grade1, grade2, grade3, grade4, grade5, grade6, grade7, grade8, grade9;

to

String grade1, grade2, grade3, grade4, grade5, grade6, grade7, grade8, grade9;

Since calcGrade() returns a String and not an int .