printf %7s
时间: 2024-04-18 14:22:33 浏览: 9
printf %7s 是一个格式化输出函数,用于将字符串按照指定的格式输出到屏幕上。其中 %7s 表示输出一个字符串,并且占据7个字符的宽度。
如果输出的字符串长度小于7个字符,则会在左侧用空格进行填充,使得输出的字符串占据7个字符的宽度。如果输出的字符串长度大于7个字符,则会按照实际长度进行输出,不会进行截断。
例如,如果有一个字符串 "Hello",使用 printf("%7s", "Hello") 进行输出,那么输出结果为 " Hello",其中前面有两个空格进行填充,使得输出的字符串占据7个字符的宽度。
相关问题
优化代码void lucai() { int j; char b[6][30]={"卤猪脚","卤鸭脚","金丝炸蛋","虎皮凤爪","叉烧","腊肠"}; { float price[6]={13,5,4,4,5,5}; printf("\n"); printf("卤菜推荐\n"); printf(" %-6s%-6s%\n", "\t名称 ", "\t单价\n "); printf(" %-7s%-7s%\n", "\t卤猪脚", "\t13\n"); printf(" %-7s%-7s%\n", "\t卤鸭脚", "\t5\n"); printf(" %-7s%-7s%\n", "\t金丝炸蛋", "\t4\n"); printf(" %-7s%-7s%\n", "\t虎皮凤爪", "\t4\n"); printf(" %-7s%-7s%\n", "\t叉烧", "\t5\n"); printf(" %-7s%-7s%\n", "\t腊肠", "\t5\n"); } }
这段代码可以进行如下优化:
1. 使用常量来保存菜品名称和价格,避免魔法数字的使用。例如可以使用以下代码:
```c
const char* names[] = {"卤猪脚", "卤鸭脚", "金丝炸蛋", "虎皮凤爪", "叉烧", "腊肠"};
const float prices[] = {13.0f, 5.0f, 4.0f, 4.0f, 5.0f, 5.0f};
const int numDishes = 6;
```
2. 使用循环来输出菜品列表。例如可以使用以下代码:
```c
printf("\n卤菜推荐\n");
printf("%-10s%-10s\n", "名称", "单价");
for (int i = 0; i < numDishes; ++i) {
printf("%-10s%-10.1f\n", names[i], prices[i]);
}
```
3. 去除不必要的大括号。例如可以使用以下代码:
```c
void lucai() {
const char* names[] = {"卤猪脚", "卤鸭脚", "金丝炸蛋", "虎皮凤爪", "叉烧", "腊肠"};
const float prices[] = {13.0f, 5.0f, 4.0f, 4.0f, 5.0f, 5.0f};
const int numDishes = 6;
printf("\n卤菜推荐\n");
printf("%-10s%-10s\n", "名称", "单价");
for (int i = 0; i < numDishes; ++i) {
printf("%-10s%-10.1f\n", names[i], prices[i]);
}
}
```
优化代码void yinliao() { int l; char d[6][40]={"海南老盐水","鸭屎香柠檬茶","斑斓香茅冰饮","豆奶","可乐/雪碧","LED气泡水"}; { float price[6]={16,18,12,9,3,9}; printf("\n"); printf("饮料推荐\n"); printf(" %-6s%-6s%\n", "\t名称 ", "\t单价\n "); printf(" %-7s%-7s%\n", "\t海南老盐水", "\t16\n"); printf(" %-7s%-7s%\n", "\t鸭屎香柠檬茶", "\t18\n"); printf(" %-7s%-7s%\n", "\t斑斓香茅冰饮", "\t12\n"); printf(" %-7s%-7s%\n", "\t豆奶", "\t9\n"); printf(" %-7s%-7s%\n", "\t可乐/雪碧", "\t3\n"); printf(" %-7s%-7s%\n", "\tLED气泡水", "\t9\n"); } }
这段代码可以进行如下优化:
1. 使用常量来保存饮料名称和价格,避免魔法数字的使用。例如可以使用以下代码:
```c
const char* names[] = {"海南老盐水", "鸭屎香柠檬茶", "斑斓香茅冰饮", "豆奶", "可乐/雪碧", "LED气泡水"};
const float prices[] = {16.0f, 18.0f, 12.0f, 9.0f, 3.0f, 9.0f};
const int numDrinks = 6;
```
2. 使用循环来输出饮料列表。例如可以使用以下代码:
```c
printf("\n饮料推荐\n");
printf("%-10s%-10s\n", "名称", "单价");
for (int i = 0; i < numDrinks; ++i) {
printf("%-10s%-10.1f\n", names[i], prices[i]);
}
```
3. 去除不必要的大括号。例如可以使用以下代码:
```c
void yinliao() {
const char* names[] = {"海南老盐水", "鸭屎香柠檬茶", "斑斓香茅冰饮", "豆奶", "可乐/雪碧", "LED气泡水"};
const float prices[] = {16.0f, 18.0f, 12.0f, 9.0f, 3.0f, 9.0f};
const int numDrinks = 6;
printf("\n饮料推荐\n");
printf("%-10s%-10s\n", "名称", "单价");
for (int i = 0; i < numDrinks; ++i) {
printf("%-10s%-10.1f\n", names[i], prices[i]);
}
}
```