C语言入门篇--局部全局变量的作用域及生命周期

#include <stdio.h>
int global = 2020;//全局变量
int main()
{
	int local = 2021;//局部变量
	int global = 2022;//局部变量
	printf("global = %d\n", global);
	return 0;
}

#include <stdio.h>
double weight = 45.5;//全局变量
void fun()
{
	printf("%f\n", weight);
	printf("%f\n", high);//error！
}
int main()
{
	double high = 180.5;//局部变量
	printf("%f\n", weight);
	printf("%f\n", high);
    fun();
	return 0;
}

#include <stdio.h>

int main()
{
	printf("%f\n", weight);//error！
}	
	return 0;
}
double weight = 45.5;

#include <stdio.h>

int main()
{
	int num1 = 0;
	int num2 = 0;
	int sum = 0;
	printf("输入两个操作数:>");
	scanf("%d %d", &num1, &num2);
	sum = num1 + num2;
	printf("sum = %d\n", sum);

	return 0;
}