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 ...
publicclassEmptyStringExample{publicstaticvoidmain(String[]args){Stringstr="";// 空字符串// 判断字符串是否为空字符串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");}str="Hello";// 判断字符串是否为空字符串if(str.isEmpty()){S...
/*** Returns true if the string is null or 0-length.* @param str the string to be examined...
public class StringCheckExample { public static void main(String&&&&args) { // 定义一个可能为null或空的String变量 String myString = 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()) { ...
String is emptyString is not emptyStringNotNullOrEmptyStringIsEmptyStringNotEmpty 旅行图 最后,我们再用mermaid语法绘制一个旅行图,表示我们判断字符串是否为null或者是空字符串的旅程: journey title Journey of String Evaluation section Check String
2. StringisBlank()Example Java program to check if a given string is blank or not. "ABC".isBlank() //false " ABC ".isBlank() //false " ".isBlank() //true "".isBlank() ) //true 3. Difference betweenisBlank()andisEmpty()
Example: Check if a string is a valid shuffle of two other strings import java.util.Arrays; class Test { // length of result string should be equal to sum of two strings static boolean checkLength(String first, String second, String result) { if (first.length() + second.length() !=...
* @param cs the CharSequence to check, may be null * @return {@code true} if the CharSequence is empty or null * @since 3.0 Changed signature from isEmpty(String) to isEmpty(CharSequence) */ publicstaticbooleanisEmpty(finalCharSequence cs) { ...
String str = "..."; if (str != null && !str.trim().isEmpty()) { // 字符串不为空操作 } 集合判空 集合类(如List、Set、Map等)可能为空或者没有元素,通常我们使用isEmpty()来检查: List<String> list = ...; if (list != null && !list.isEmpty()) { ...