实验一-熟悉C语言编程环境

#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
",letter,digit,other);

    return 0;

}

#include<stdio.h>
int main(void)
{
    int choice,i;
    double price;

    for(i=1;i<=5;i++){
       
        printf("[1]Select crisps 
");
        printf("[2]Select popcorn 
");
        printf("[3]Select chocolate 
");
        printf("[4]Select cola 
");
        printf("[0] exit 
");

        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=%0.1f
",price);

    }
        printf("Thanks 
");

        return 0;

}

#include<stdio.h>
int main(void)
{
    double value1,value2;
    char op;

    printf("Type in an expression:");
    scanf("%if%c%if",&value1,&op,&value2);
    switch(op){
    case'+':
        printf("=%.2f
",value1+value2);
        break;
    case'-':
        printf("=%.2f
",value1-value2);
        break;
    case'*':
        printf("=%.2f
",value1*value2);
        break;
    case'/':
        printf("=%.2f
",value1/value2);
        break;
    default:
        printf("Unknown operator
");
        break;

    }

    return 0;
}

#include<stdio.h>
int main(void)
{
    double value1,value2;
    char op;

    printf("Type in an expression:");
    scanf("%if%c%if",&value1,&op,&value2);
    if(op=='+')
        printf("=%.2f
",value1+value2);
    else if(op=='-')
        printf("=%.2f
",value1-value2);   
    else if(op=='*')
        printf("=%.2f
",value1*value2);
    else if(op=='/')
        if(value2!=0)
            printf("=%.2f
",value1/value2);
        else
            printf("Divisor can not be 0!
");
    else
            printf("Unknown operator!
");
    return 0;

}