我试图在我的toString方法中返回int值a,b和c,但是尽管有一个“;”,但它却显示了“;预期”。我不明白怎么了。我已经尝试过类似“ APLine.getA()”和“ getA()”的方法,但是它们都没有起作用。请帮我。我感到很难过。
public class APLine
{
private int a;
private int b;
private int c;
private int x;
private int y;
public APLine()
{
a = 0;
b = 0;
c = 0;
x = 0;
y = 0;
}
public APLine(int A, int B, int C)
{
a = A;
b = B;
c = C;
}
public void setA(int A)
{
a = A;
}
public void setB(int B)
{
b = B;
}
public void setC(int C)
{
c = C;
}
public int getA()
{
if(a != 0)
{
return a;
}
}
public int getB()
{
if(b != 0)
{
return b;
}
}
public int getC()
{
return c;
}
public double getSlope()
{
return (double)(-a)/b;
}
public boolean isOnLine(int x, int y)
{
if(a*x + b*y + c == 0)
{
return true;
}
else
{
return false;
}
}
public String toString()
{
return ""a,b,c;
}
}
这是主要方法。
class Main {
public static void main(String[] args) {
APLine myLine = new APLine(5, 4, -17);
System.out.println("The slope is: "+ myLine.getSlope());
System.out.println("Is (5, 2) on the the line? "+ myLine.isOnLine(5,2));
System.out.println("Is (1, 4) on the the line? "+ myLine.isOnLine(1,4));
myLine = new APLine(-25, 40, 30);
System.out.println("The slope is: "+ myLine.getSlope());
System.out.println("Is (5, -2) on the the line? "+ myLine.isOnLine(5,-2));
System.out.println("Is (6, 3) on the the line? "+ myLine.isOnLine(6,3));
}
}
这就是编译器显示的内容。
APLine.java:78: error: ';' expected
return ""a,b,c;
^
APLine.java:78: error: ';' expected
return ""a,b,c;
^
APLine.java:78: error: not a statement
return ""a,b,c;
^
APLine.java:78: error: ';' expected
return ""a,b,c;
^
APLine.java:78: error: not a statement
return ""a,b,c;
^
5 errors
答案 0 :(得分:0)
更改
public String toString(){return ""a,b,c;}
到
public String toString(){return String.format("%s,%s,%s", a,b,c);}
您的表达式无效。