我正在尝试解决来自 Java 的艺术与科学的练习,二次方程的解决方案。
import acm.program.*;
public class QuadraticEquation extends ConsoleProgram {
public void run(){
println("Enter coefficients for quadratic equation");
int a = readInt("Enter first number: ");
int b = readInt("Enter second number: ");
int c = readInt("Enter third number: ");
double result = quadratic(a,b,c);
println("The first solution is: " + result);
}
private double quadratic(int a, int b, int c){
double underSquare = (b*b-4*a*c);
double x = (-b+Math.sqrt(b*b-(4*a*c)))/(2*a);
if (underSquare < 0) {
return null;
} else {
return (x);
}
}
}
我有一个错误:
return null;
说:
类型不匹配:无法从 null 转换为 double
我真的不明白这个错误是什么,我应该如何正确解决这个问题?