# Java 程序：找到三個數字中最大的一個 > 原文： [https://beginnersbook.com/2017/09/java-program-to-find-largest-of-three-numbers/](https://beginnersbook.com/2017/09/java-program-to-find-largest-of-three-numbers/) 在這里，我們將編寫兩個 java 程序來查找三個數字中最大的程序。 1）使用`if-else..if`2）使用嵌套的`If` 要了解這些程序，您應該掌握 Java 中[`if..else-if`語句](https://beginnersbook.com/2017/08/if-else-statement-in-java/)的知識。如果您是 java 新手，請從[核心 Java 教程](https://beginnersbook.com/java-tutorial-for-beginners-with-examples/)開始。 ## 示例 1：使用`if-else..if`查找三個數字中的最大數字 ```java public class JavaExample{ public static void main(String[] args) { int num1 = 10, num2 = 20, num3 = 7; if( num1 >= num2 && num1 >= num3) System.out.println(num1+" is the largest Number"); else if (num2 >= num1 && num2 >= num3) System.out.println(num2+" is the largest Number"); else System.out.println(num3+" is the largest Number"); } } ``` 輸出： ```java 20 is the largest Number ``` ## 示例 2：使用嵌套`if`在三個數字中查找最大數字 ```java public class JavaExample{ public static void main(String[] args) { int num1 = 10, num2 = 20, num3 = 7; if(num1 >= num2) { if(num1 >= num3) /* This will only execute if conditions given in both * the if blocks are true, which means num1 is greater * than num2 and num3 */ System.out.println(num1+" is the largest Number"); else /* This will only execute if the condition in outer if * is true and condition in inner if is false. which * means num1 is grater than num2 but less than num3. * which means num3 is the largest */ System.out.println(num3+" is the largest Number"); } else { if(num2 >= num3) /* This will execute if the condition in outer if is false * and inner if is true which means num3 is greater than num1 * but num2 is greater than num3\. That means num2 is largest */ System.out.println(num2+" is the largest Number"); else /* This will execute if the condition in outer if is false * and inner if is false which means num3 is greater than num1 * and num2\. That means num3 is largest */ System.out.println(num3+" is the largest Number"); } } } ``` 輸出： ```java 20 is the largest Number ```