这里的obj.equals("")是一个判断条件,如果满足条件,即对象的值为空字符串,就会执行if语句块中的代码。你可以在if语句块中编写处理对象为空的逻辑。 示例代码 下面是一个完整的示例代码,演示了如何判断对象是否为null和空。 publicclassNullAndEmptyCheck{publicstaticvoidmain(String[]args){Objectobj1=null;Object...
publicclassCheckNullInArray{publicstaticvoidmain(String[]args){String[]array=newString[5];array[0]="value1";array[1]=null;array[2]="value3";array[3]="value4";array[4]=null;StringvalueToCheck="value3";booleanisNull=false;for(Stringvalue:array){if(value!=null&&value.equals(valueToCheck...
println("The string is not null."); } Employing the Objects.isNull() method: In Java 8 and later versions, you can use the Objects.isNull() method from the java.util.Objects class to check if a string is null. This method returns true if the provided object is null; otherwise, it...
Check If Int Is Null In Java Int is primitive data type in java and Such data types in java stores data in binary form in memory by default. That means they can’t be null in java .So we can’t check int for a null value . On the other hand, Integer is an object and it can...
Firstly, we check if the string is null by comparing it with the value null using the == operator. If the string is indeed null, it means it is empty as well, and we can consider it as such. If the string is not null, we proceed to check its length using the length() method....
* 对象为new,但对象中的属性都为null * **/publicclassCheckObjectIsNullUtils {/*** 判断对象是否为空,且对象的所有属性都为空 * ps: boolean类型会有默认值false 判断结果不会为null 会影响判断结果 * 序列化的默认值也会影响判断结果 * *@
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...
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) {
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."); ...
findMax(null); } privatestaticvoid findMax(int[] arr){ int max = arr[0]; //check other elements in loop } 这会在第6行导致 NullPointerException。因此,访问空 对象的任何字段,方法或索引会导致 NullPointerException,如上面的示例所示。避免 NullPointerException的 常见方法是检查 null: ...