温习 C语言

/******大小写字母转换******/




/*#include<stdio.h>
void main()
{
char a,b;
a='a';
b='b';
a=a-32;
b=b-32;
printf("%c,%c\n%d,%d\n",a,b,a,b);
}*/




/******输出格式长度*******/




/*#include<stdio.h>
void main()
{
int a=90;
printf("%d\n",3);
printf("%2d\n",3);
printf("%8d\n",36500);
printf("%e\n",3.14);
printf("%6f\n",3.14);
printf("%9.0f\n",3.1415);
}*/




/******输出hello!******/




/*#include<stdio.h>
void main()
{
char c;
printf("Enter a string:");
c=getchar();
putchar(c);
c=getchar();
putchar(c);
c=getchar();
putchar(c);
c=getchar();
putchar(c);
c=getchar();
putchar(c);
c=getchar();
putchar(c);

}*/




/******输出一个汉字，一个汉字占两个字节******/




/*#include<stdio.h>
void main()
{
char c1,c2;
printf("Enter an chinese character:");
c1=getchar();
c2=getchar();
printf("the chinese character entered is:");
putchar(c1);
putchar(c2);
putchar('\n');

}*/




/******强制类型转换******/




/*
#include<stdio.h>
void main()
{
float f=5.75;
printf("(int)f=%d,f=%f\n",(int)f,f);
}*/




/******算术运算******/




/*#include<stdio.h>
void main()
{
int z=10,q=3,a=8,i=1,j=2,k=3;
char c='k';
float x=3e+5,y=0.85;
printf("%d,%d\n",'a'+5<c,-i-2*j>=k+1);  //1,0
printf("%d,%d\n",1<j<5,x-5.25<=x+y);    //1,1
printf("%f\n",x+y);  //3e+5 + 0.85
printf("%d,%d\n",i+j+k==-2*j,k==j==i+5);  //0,0
printf("%d,%d\n",z/q,z%q);
printf("%d\n",++a);//9
printf("%d\n",--a);//8
printf("%d\n",a++);//8,i=9
printf("%d\n",a--);//9,i=8
printf("%d\n",-a++);//-8,i=9
printf("%d\n",-a--);//-9,i=8


}*/




/******输出两个数中的大小******/




/*#include<stdio.h>
void main()
{
int a,b;
printf("\n input two numbers:  ");
scanf("%d%d",&a,&b);
printf("max=%d",a>b?a:b);
}*/




/******统计输入字符个数******/




/*
#include<stdio.h>
void main()
{
int n=0;
while(getchar()!='\n')

n++;
printf("%d",n);

// putchar(c);
// printf("%c",c);
}*/






/******while的使用******/






/*
#include<stdio.h>
void main()
{
int a=0,n,num;
scanf("%d",&n);
while(n--)
{
printf("num=%d",num=a++*2);
printf("a=%d,n=%d\n",a,n);
}
}*/




/******用do-while语句计算1加到100******/




/*#include<stdio.h>
void main()
{
int i=1,sum=0;
do
{
sum+=i;
i++;
}
while(i<=100);
printf("%d",sum);
}*/