1. Overview

1.概述

In this article, we are going to address the “variable might not have been initialized” error in Java programs. This error occurs when we declare a variable without initializing it. Therefore, we will discuss the error with an example and offer some solutions to solve it.

在这篇文章中，我们要解决Java程序中的 “变量可能没有被初始化 “的错误。当我们声明一个变量而不对其进行初始化时就会出现这个错误。因此，我们将通过一个例子来讨论这个错误，并提供一些解决方案来解决它。

2. Java Error: “variable might not have been initialized”

2.Java错误 “变量可能没有被初始化”

Should we declare a local variable without an initial value, we get an error. This error occurs only for local variables since Java automatically initializes the instance variables at compile time (it sets 0 for integers, false for boolean, etc.). However, local variables need a default value because the Java compiler doesn’t allow the use of uninitialized variables.

如果我们声明一个没有初始值的局部变量，我们会得到一个错误。这个错误只发生在局部变量上，因为Java在编译时自动初始化了实例变量（它为整数设置0，为布尔值设置false，等等）。然而，局部变量需要一个默认值，因为Java编译器不允许使用未初始化的变量。

Let’s write a simple code having an uninitialized variable:

让我们写一段简单的代码，有一个未初始化的变量。

public class VariableMightNotHaveBeenInitializedError {
    public static void main(String[] args) {
        int sum;
        int[] list = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9};
        for (int i = 0; i < list.length; i++) {
            sum += list[i];
        }
        System.out.println("sum is: " + sum);
    }
}

In this code, we calculate the sum of a list of integer numbers. Then, we put it in the variable sum. The following error appears at compile time:

在这段代码中，我们计算了一个整数列表的总和。然后，我们把它放在变量sum.中，在编译时出现以下错误。

3. Solutions

3.解决方案

To solve the error, we should simply assign a value to the variable when creating it:

为了解决这个错误，我们应该在创建该变量时简单地给它赋值。

public class VariableMightNotHaveBeenInitializedError {
    public static void main(String[] args) {
        int sum = 0;
        int[] list = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9};
        for (int i = 0; i < list.length; i++) {
            sum += list[i];
        }
        System.out.println("sum is: " + sum);
    }
}

Finally, by running the code, we get results without any errors:

最后，通过运行代码，我们得到的结果没有任何错误。

4. Conclusion

4.总结

In this tutorial, we discussed how uninitialized variables in Java cause getting errors. Then, we wrote a simple Java code and declared a local variable to hold the result of an operation without any error.

在本教程中，我们讨论了Java中未初始化的变量是如何导致获得错误的。然后，我们写了一段简单的Java代码，并声明了一个局部变量来保存一个操作的结果，没有任何错误。