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Write a Java Program to Check if a String is Empty or Null
PROGRAM: Java Program to Check if a String is Empty or Null
/*Java Program to Check if a String is Empty or Null*/
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 ” + isNullEmpty(str1));
// check if str2 is null or empty
System.out.println(“str2 is ” + isNullEmpty(str2));
// check if str3 is null or empty
System.out.println(“str3 is ” + isNullEmpty(str3));
}
// method check if string is null or empty
public static String isNullEmpty(String str) {
// check if string is null
if (str == null) {
return “NULL”;
}
// check if string is empty
else if(str.isEmpty()){
return “EMPTY”;
}
else {
return “neither NULL nor EMPTY”;
}
}
}
2: Check if String with spaces is Empty or Null
class Main {
public static void main(String[] args) {
// create a string with white spaces
String str = ” “;
// check if str1 is null or empty
System.out.println(“str is ” + isNullEmpty(str));
}
// method check if string is null or empty
public static String isNullEmpty(String str) {
// check if string is null
if (str == null) {
return “NULL”;
}
// check if string is empty
else if (str.trim().isEmpty()){
return “EMPTY”;
}
else {
return “neither NULL nor EMPTY”;
}
}
}
