Input a string which contains (a,b,c,...,z,A,B,C,...Z,\t and space ' ') and end of '\n',Please convert all the character into lower case and delete all the space and \t.(1 <= string length <= 20)
Output format:
no '\n'
For example:
[Input]
I L o  Ve       YoU
[Output]
iloveyou
The input "I L o Ve YoU" means that:
I+' '+L+' '+o+' '+' '+V+e+'\t'+Y+o+U+'\n'

#include<stdio.h>
int main()
{

    char ch;
    
    while ((scanf("%c", &ch) == 1) && (ch != '\n'))
    {
        if ((ch >= 'A') && (ch <= 'Z'))
        {
            ch = ch - 'A' + 'a';
        }
        else if ((ch >= 'a') && (ch <= 'z'))
        {

        }
        else
        {
            continue;
        }
        printf("%c", ch);
    }
    printf("\n");
    return 0;
}

明白了，谢谢啦！

还有，能不能用getchar()函数？
（这个我不太会用）

把scanf("%c",&ch);改成getchar(ch)就行了~

好的，谢谢你啦！

突然纠结没上机调试，其实书本写法是ch=getchar()
~~~