英文:
Type Mismatch: Can't convert double into double[]
问题
当我运行这段Java代码时，出现了错误。我是Java的新手。有人可以帮忙吗？
package raza.project.arrays;import java.util.*;public class arraysLearning {public static void main(String[] args) {int [] numbers = { 25,36,38,63,89,52,74};double[] med = median(numbers);}// 返回一个数组中的中位数值，不改变参数数组public static double median(int[] numbers) {int[] tmp = Arrays.copyOf(numbers, numbers.length);Arrays.sort(tmp);int mid = tmp.length/2; // 注意：整数除法if (tmp.length%2 == 0) { // 偶数长度？return (tmp[mid-1]+tmp[mid])/2.0; // 浮点数除法}else {return tmp[mid];}}}
Java编译器是最新的JDK14
英文:
When i am running this java code i got error. I am new to java. Can anyone help.
package raza.project.arrays;import java.util.*;public class arraysLearning {public static void main(String[] args) {int [] numbers = { 25,36,38,63,89,52,74};double[] med = median(numbers);}//Return the median value of an array of numbers//without changing the parameter arraypublic static double median(int[] numbers) {int[] tmp = Arrays.copyOf(numbers, numbers.length);Arrays.sort(tmp);int mid = tmp.length/2; // Note: int divisionif (tmp.length%2 == 0) { // even length?return (tmp[mid-1]+tmp[mid])/2.0; //float division}else {return tmp[mid];}}}
java compiler is latest jdk14
答案1
得分: 2
这个方法：public static double median(int[] numbers) 返回一个 double 类型的对象。
当你想调用一个方法并将结果存储在一个变量中时，你需要确保变量的类型与方法返回的类型相同。
你需要更改这行代码：
double[] med = median(numbers);
为
double med = median(numbers);
在这里，变量的类型是 double，而方法返回一个 double。两者类型匹配，编译器满意，你的代码可以编译。但在你的情况下，类型是 double[]，而方法返回一个 double 对象... 没有匹配，所以你的代码无法编译。
英文:
This method: public static double median(int[] numbers) returns an object of type double.
When you want to call a method a get the result in a variable, you need to make sure the variable is of the same type as the type returned by the method.
You need to change this line:
double[] med = median(numbers);
With
double med = median(numbers);
Here, the variable is of type double and the method returns a double. Both types matches, the compiler is happy and your code compiles. But in your case, the type is double[] and the method returns a double object... There is no match, so your code doesn't compile
答案2
得分: 0
Your median() method is supposed to return a "double" value and not an array of double values.
public static void main(String[] args) {int[] numbers = {25, 36, 38, 63, 89, 52, 74};double med = median(numbers); // remove [] on this line.}
英文:
Your median() method is supposed to return a "double" value and not an array of double values.
public static void main(String[] args) {int[] numbers = {25,36,38,63,89,52,74};double med = median(numbers); // remove [] on this line.}
答案3
得分: 0
You are returning a double value but you are returning it to a double array, there is type mismatch.
你返回一个 double 值，但你将它返回给一个 double 数组，类型不匹配。
英文:
You are returning a double value but you are returning it to a double array, there is type mismatch.
import java.util.*;
public class Test {
public static void main(String[] args) {int [] numbers = { 25,36,38,63,89,52,74};double med = median(numbers);}//Return the median value of an array of numbers//without changing the parameter arraypublic static double median(int[] numbers) {int[] tmp = Arrays.copyOf(numbers, numbers.length);Arrays.sort(tmp);int mid = tmp.length/2; // Note: int divisionif (tmp.length%2 == 0) { // even length?return (tmp[mid-1]+tmp[mid])/2.0; //float division}else {return tmp[mid];}}
}
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