第三章
例3-1
#include<stdio.h>
int main(void)
{
int mynumber=38;
int yournumber;
printf("Input your number:");
scanf("%d",&yournumber);
if(yournumber==mynumber)
printf("OK!you are right!\n");
else
if(yournumber>mynumber)
printf("Sorry!your number is bigger than my number!\n");
else
printf("Sorry!your number is smaller than my number!\n");
return 0;
}
例3-2
#include<stdio.h>
int main(void)
{
int number;
printf("Enter a number:");
scanf("%d",&number);
if(number%2==0){
printf("The number is even.\n");
}
else{
printf("The number is odd.\n");
}
return 0;
}
例3-3
#include<stdio.h>
int main(void)
{
int count,i,n;
double grade,total;
printf("Enter n:");
scanf("%d",&n);
total=0;
count=0;
for(i=1;i<=n;i++){
printf("Enter grade#%d:",i);
scanf("%lf",&grade);
total=total+grade;
if(grade<60){
count++;
}
}
printf("Grade average=%.2f\n",total/n);
printf("Number of failures=%d\n",count);
return 0;
}
例3-4
#include<stdio.h>
int main(void)
{
double x,y;
printf("Enter x:");
scanf("%lf",&x);
if(x<0){
y=0;
}
else if(x<=15){
y=4*x/3;
}
else{
y=2.5*x-10.5;
}
printf("f(%.2f)=%.2f\n",x,y);
return 0;
}
例3-5
#include<stdio.h>
int main(void)
{
double value1,value2;
char op;
printf("Type in an expression:");
scanf("%lf%c%lf",&value1,&op,&value2);
if(op=='+')
printf("=%.2f\n",value1+value2);
else if(op=='-')
printf("=%.2f\n",value1-value2);
else if(op=='/')
printf("=%.2f\n",value1/value2);
else
printf("Unknown operator\n");
return 0;
}
例3-7
#include<stdio.h>
int main(void)
{
int digit,letter,other;
char ch;
int i;
digit=letter=other=0;
printf("Enter 10 characters:");
for(i=1;i<=10;i++){
ch=getchar();
if((ch>='a'&&ch<='z')||(ch>='A'&&ch<='Z'))
letter++;
else if(ch>='0'&&ch<='9')
digit++;
else
other++;
}
printf("letter=%d,digit=%d,other=%d\n",letter,digit,other);
return 0;
}
例3-8
#include<stdio.h> int main(void) { int choice,i; double price; for(i=1;i<=5;i++){ printf("[1]Select crisps\n"); printf("[2]Select popcorn\n"); printf("[3]select chocolate\n"); printf("[4]Select cola\n"); printf("[0]exit\n"); printf("Enter choice:"); scanf("%d",&choice); if(choice==0) break; switch(choice){ case 1:price=3.0;break; case 2:price=2.5;break; case 3:price=4.0;break; case 4:price=3.5;break; default:price=0.0;break; } printf("price=%0.lf\n",price); } printf("Thanks\n"); return 0; }
例3-9
#include<stdio.h>
int main(void)
{
double value1,value2;
char op;
printf("Type in an expression:");
scanf("%lf%c%lf",&value1,&op,&value2);
switch(op){
case'+':
printf("=%.2f\n",value1+value2);
break;
case'-':
printf("=%.2f\n",value1-value2);
break;
case'/':
printf("=%.2f\n",value1/value2);
break;
default:
printf("Unknown operator\n");
break;
}
return 0;
}
例3-10
#include<stdio.h> int main(void) { int blank,digit,other; char ch; int i; blank=digit=other=0; printf("Enter 10 character:"); for(i=1;i<=10;i++){ ch=getchar(); switch(ch){ case' ': case'\n': blank++; break; case'0':case'1':case'2':case'3':case'4': case'5':case'6':case'7':case'8':case'9': digit++; break; default: other++; break; } } printf("blank=%d,digit=%d,other=%d",blank,digit,other); return 0; }
例3-11
#include<stdio.h> int main(void) { double value1,value2; char op; printf("Type in an expression:"); scanf("%lf%c%lf",&value1,&op,&value2); if(op=='+') printf("=%.2f\n",value1+value2); else if(op=='-') printf("=%.2f\n",value1-value2); else if(op=='*') printf("=%.2f\n",value1*value2); else if(op=='/') if(value2!=0) printf("=%.2f\n",value1/value2); else printf("Divisor can be 0!\n"); else printf("Unknown operator!\n"); return 0; }
心得:
如果寝室长不告诉我有插入代码这回事,我估计会一直复制粘贴下去。真是极其恐怖极其不美观的事情。然后幸亏之前有把代码截图,不然真心不堪入目了。我百度了一下老师说的==和=的区别,大概意思懂了,=是赋值,==好像是说有点判断的意思,判断输入的数字是否等于这个数字云云。如果有误是百度坑我。==、其实如果要我一边打一边看书理解还是不大可能的,不过打多了就有一些基本的内容可以按照自己的方式去理解了。虽然不是用上专业术语,但是对自己的c语言学习有一定的帮助。准备先把代码打完再好好看书。就是这样,(>^ω^<)