09-把字符串中的大写变为小写

int main()

{

char str[] = "This Is a c Program";

int i = 0;

while (str[i] != '\0')

{

if (str[i]>'A'&&str[i]<'Z')

{

str[i] += 32;

}

i++;

}

puts(str);

return 0;

}