语句

if...else

#include <stdio.h>

int main(void)
{

	int a = 60;
	float b = 70.5;

	if (a > 60)
	{
		printf("大于 60");
	}
	else if (a < b)
	{
		printf("a 小于 b");
	}
	else
	{
		printf("小于 60");
	}
}

三目运算符

#include <stdio.h>

int main(void)
{

	int a = 60;
	float b = 70.5;

	printf(a > 60 ? ("大于 60") : "a 小于 b");
}

switch

#include <stdio.h>

int main(void)
{

	char c;
	c = getchar();

	switch (c) // 参数只能是整型变量
	{
	case '1':
		printf("OK\n");
		break; // switch遇到break就中断了
	case '2':
		printf("not OK\n");
		break;
	default: // 如果上面的条件都不满足，那么执行default
		printf("are u ok?\n");
	}
}

while

#include <stdio.h>

int main()
{
	int a = 20;
	while (a > 10)
	{
		scanf("%d", &a);
		printf("a = %d\n", a);
	}

	return 0;
}

do while

#include <stdio.h>

int main()
{
	int a = 1;
	do
	{
		a++;
		printf("a = %d\n", a);
	} while (a < 10);

	return 0;
}

for

#include <stdio.h>

int main()
{
	int i;
	int sum = 0;
	for (i = 0; i <= 100; i++)
	{
		sum += i;

	}

	printf("sum = %d\n", sum);

	return 0;
}

跳转语句

break

#include <stdio.h>

int main()
{
	int i = 0;
	while (1)
	{
		i++;
		printf("i = %d\n", i);

		if (i == 10)
		{
			break; //跳出while循环
		}
	}

	int flag = 0;
	int m = 0;
	int n = 0;

	for (m = 0; m < 10; m++)
	{
		for (n = 0; n < 10; n++)
		{
			if (n == 5)
			{
				flag = 1;
				break; //跳出for (n = 0; n < 10; n++)
			}
		}

		if (flag == 1)
		{
			break; //跳出for (m = 0; m < 10; m++)
		}
	}

	return 0;
}

continue

#include<stdio.h>

int main()
{
	int sum = 0;           //定义变量sum

	for (int i = 1; i <= 100; i++)
	{
		if (i % 2 == 0)   //如果i是一个偶数，执行if语句中的代码
		{
			continue;      //结束本次循环
		}
		sum += i;          //实现sum和i的累加
	}

	printf("sum = %d\n", sum);

	return 0;
}

goto

无条件跳转，尽量少用

#include <stdio.h>

int main()
{
	goto End; //无条件跳转到End的标识
	printf("aaaaaaaaa\n");

End:
	printf("bbbbbbbb\n");

	return 0;
}