Java String isEmpty() 使用方法及示例

Java String (String) Methods

The Java String isEmpty() method checks if the string is empty.

The syntax of the string isEmpty() method is:

string.isEmpty()

Here, string is an object of the String class.

isEmpty() Parameter

• Without any parameters

isEmpty() Return Value

• If the string is empty (length is 0)Returns true

• If the string is not emptyReturns false

Example: Java String isEmpty()

class Main {
　　public static void main(String[] args) {
　　　　String str1　= "Java Programming";
　　　　String str2　= "";
　　　　System.out.println(str1.isEmpty());　//　false
　　　　System.out.println(str2.isEmpty());　//　true
　　}
}

Note:An uninitialized string is not an empty string. If isEmpty() is used on an uninitialized string, an error will be thrown.

Java String (String) Methods