Java如何从try,catch和最后返回一个值?
作者:互联网
因此,当我在“try {}”中执行块代码时,我尝试返回一个值,它会出现“无返回值”.这是我使用的代码,代表我的问题.
import org.w3c.dom.ranges.RangeException;
public class Pg257E5
{
public static void main(String[]args)
{
try
{
System.out.println(add(args));
}
catch(RangeException e)
{
e.printStackTrace();
}
finally
{
System.out.println("Thanks for using the program kiddo!");
}
}
public static double add(String[] values) // shows a commpile error here that I don't have a return value
{
try
{
int length = values.length;
double arrayValues[] = new double[length];
double sum =0;
for(int i = 0; i<length; i++)
{
arrayValues[i] = Double.parseDouble(values[i]);
sum += arrayValues[i];
}
return sum; // I do have a return value here. Is it because if the an exception occurs the codes in try stops and doesn't get to the return value?
}
catch(NumberFormatException e)
{
e.printStackTrace();
}
catch(RangeException e)
{
throw e;
}
finally
{
System.out.println("Thank you for using the program!");// so would I need to put a return value of type double here?
}
}
}
基本上,我遇到的问题是“当你使用try和catch块时,你如何返回一个值?
解决方法:
要在使用try / catch时返回值,可以使用临时变量,例如
public static double add(String[] values) {
double sum = 0.0;
try {
int length = values.length;
double arrayValues[] = new double[length];
for(int i = 0; i < length; i++) {
arrayValues[i] = Double.parseDouble(values[i]);
sum += arrayValues[i];
}
} catch(NumberFormatException e) {
e.printStackTrace();
} catch(RangeException e) {
throw e;
} finally {
System.out.println("Thank you for using the program!");
}
return sum;
}
否则,您需要在没有抛出的每个执行路径(try block或catch block)中返回.
标签:java,return-value,exception,double,try-catch 来源: https://codeday.me/bug/20191001/1840336.html