java中toString方法中返回值的问题
我试图在我的toString方法中返回int值a、b和c,但它表示“预期”,尽管有一个“;”。我不明白怎么了。我试过“APLine.getA()”和“getA()”之类的东西,但都不起作用。请帮帮我。我感到很难过java中toString方法中返回值的问题,java,Java,我试图在我的toString方法中返回int值a、b和c,但它表示“预期”,尽管有一个“;”。我不明白怎么了。我试过“APLine.getA()”和“getA()”之类的东西,但都不起作用。请帮帮我。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
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;
}
}
这是主要的方法
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
改变
到
您的表达式无效。请尝试
“”+a+b+c代码>。但是,这将返回类似于234
的内容。所以可能返回“a=“+a+”\nb=“+b+”\nc=“+c
更像您想要的东西您在toString()
方法中尝试了什么?您也可以尝试使用String.join
静态方法。一个示例用法是:返回String.join(“,”,a,b,c)
String.join()
将不起作用@prasadHowpublic int getA(){if(a!=0){return a;}}
甚至编译?在所有情况下都没有返回值
public String toString(){return ""a,b,c;}
public String toString(){return String.format("%s,%s,%s", a,b,c);}