Example 1: Check if String is Empty or Null class Main { public static void main(String[] args) { // create null, empty, and regular strings String str1 = null; String str2 = ""; String str3 = " "; // check if str1 is null or empty System.out.println("str1 is " + is...
isEmpty(); // true boolean isEmpty2 = str2.isEmpty(); // false Comparing the length of the string to zero: Another approach to check for an empty string is by comparing the length of the string to zero using the length() method. If the length is zero, it indicates that the ...
The if-else approach is a straightforward method to check if a string is null or empty in Java. It involves using conditional statements to evaluate the string and perform appropriate actions based on the result. Here’s how the basic if-else approach works: Firstly, we check if the string...
publicclassStringCheckExample{ publicstaticvoidmain(String[] args){ // 定义一个可能为null或空的String变量 StringmyString=null;// 我们可以根据需要更改这个变量的值 // 判断String是否为null或空 if(myString ==null|| myString.isEmpty) { System.out.println("The string is null or empty."); }el...
if (input.isEmpty) error --> "IllegalArgumentException" } USER ||--|{ EMPTY_STRING_CHECK : "inputs" 总结 通过以上步骤,我们成功地实现了一个简单的 Java 程序,该程序能够检查用户输入的字符串是否为空,并处理相应的错误信息。希望这篇指导能够帮助新手开发者更好地理解如何处理 Java 中的空字符串问题...
Stringstr="";if(str.equals("")){System.out.println("字符串是空字符串");}else{System.out.println("字符串不是空字符串");} 1. 2. 3. 4. 5. 6. 方法二:使用isEmpty()方法 使用字符串的isEmpty()方法也可以判断字符串是否为空字符串。isEmpty()方法用于判断字符串的长度是否为0。当字符串的...
翻一下JDK的实现就会知道：其实isEmpty完全等同于string.length()==0如果String本身是null，那么使用...
翻一下JDK的实现就会知道：其实isEmpty完全等同于string.length()==0如果String本身是null，那么使用...
publicclassStringCheckExample{publicstaticvoidmain(String[] args){// 定义一个可能为null或空的String变量StringmyString=null;// 我们可以根据需要更改这个变量的值// 判断String是否为null或空if(myString ==null|| myString.isEmpty()) { System.out.println("The string is null or empty."); ...
* Checks if a CharSequence is whitespace, empty ("") or null. *@paramcs the CharSequence to check, may be null *@return{@codetrue} if the CharSequence is null, empty or whitespace *@since2.0 *@since3.0 Changed signature from isBlank(String) to isBlank(CharSequence) */publicstatic...