isEmpty
时间: 2023-09-02 22:06:16 浏览: 40
isEmpty通常指的是某个数据结构或容器是否为空。在编程中,我们经常需要判断一个字符串、数组、集合等数据结构是否为空。isEmpty通常是一个函数或方法,并返回一个布尔值,如果数据结构为空,则返回true,否则返回false。下面是一个Java中字符串判断是否为空的例子:
```java
String str = "";
if (str.isEmpty()) {
System.out.println("The string is empty.");
} else {
System.out.println("The string is not empty.");
}
```
在这个例子中,我们定义了一个空字符串str,然后使用isEmpty方法判断它是否为空。由于str是空字符串,isEmpty方法返回true,因此程序输出"The string is empty."。
相关问题
vue isEmpty
以下是一个Vue工具类中判断是否为空的例子[^1^2]:
```javascript
export default class func {
/* 不为空 */
static notEmpty(val) {
return !this.isEmpty(val);
}
/* 为空 */
static isEmpty(val) {
if (val === null || typeof val === 'undefined' || (typeof val === 'string' && val === '' && val !== 'undefined')) {
return true;
}
return false;
}
}
```
使用该工具类,你可以通过调用`isEmpty`方法来判断一个值是否为空,或者通过调用`notEmpty`方法来判断一个值是否不为空。
CString IsEmpty
CString IsEmpty is a member function of the CString class in MFC (Microsoft Foundation Classes), which is a framework for developing Windows-based applications. This function is used to check whether a CString object is empty or not.
If the CString object is empty, meaning it does not contain any characters, the IsEmpty function will return a non-zero value (TRUE). Otherwise, if the CString object has at least one character, the function will return zero (FALSE).
Here's an example of how you can use the IsEmpty function in C++:
```cpp
CString str = "Hello, world!";
if (str.IsEmpty()) {
// The string is empty
// Perform some actions
} else {
// The string is not empty
// Perform some other actions
}
```
In this example, the IsEmpty function is used to conditionally perform different actions based on whether the CString object "str" is empty or not.