# C 程序：查找兩個數字的平均值 > 原文： [https://beginnersbook.com/2017/09/c-program-to-find-the-average-of-two-numbers/](https://beginnersbook.com/2017/09/c-program-to-find-the-average-of-two-numbers/) 在這里，我們將編寫兩個 C 程序來查找兩個數字的平均值（由用戶輸入）。 ## 示例 1：編程以查找兩個數字的平均值 ```c #include <stdio.h> int main() { int num1, num2; float avg; printf("Enter first number: "); scanf("%d",&num1); printf("Enter second number: "); scanf("%d",&num2); avg= (float)(num1+num2)/2; //%.2f is used for displaying output upto two decimal places printf("Average of %d and %d is: %.2f",num1,num2,avg); return 0; } ``` 輸出： ```c Enter first number: 12 Enter second number: 13 Average of 12 and 13 is: 12.50 ``` ## 示例 2：使用函數用于查找均值的程序 在這個程序中，我們創建了一個用戶定義函數`average()`來計算平均值。用戶輸入的數字在函數調用期間傳遞給該函數。 ```c #include <stdio.h> float average(int a, int b){ return (float)(a+b)/2; } int main() { int num1, num2; float avg; printf("Enter first number: "); scanf("%d",&num1); printf("Enter second number: "); scanf("%d",&num2); avg = average(num1, num2); //%.2f is used for displaying output upto two decimal places printf("Average of %d and %d is: %.2f",num1,num2,avg); return 0; } ``` 輸出： ```c Enter first number: 20 Enter second number: 13 Average of 20 and 13 is: 16.50 ``` 查看相關的 [C 程序](https://beginnersbook.com/2015/02/simple-c-programs/)： 1. [C 程序：相加兩個數字](https://beginnersbook.com/2017/09/c-program-to-add-two-numbers/) 2. [C 程序：相乘兩個浮點數](https://beginnersbook.com/2017/09/c-program-to-multiply-two-floating-point-numbers/) 3. [C 程序：查找數組中的元素數](https://beginnersbook.com/2017/09/c-program-to-find-the-number-of-elements-in-an-array/) 4. [C 程序：展示斐波那契序列](https://beginnersbook.com/2014/06/c-program-to-display-fibonacci-series/)