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Comparing a string with the empty string (Java)
(9 answers)
How do I compare strings in Java?
(23 answers)
Closed 5 years ago.
Lets say we have a string in java. Can we compare this string to "" using the ==?
For example:
String myString = "";
if(myString == "");
Of course you can (insofar that compilation will pass), although you will probably not get the result you expect since using == will compare references not contents.
My favourite way is to use the Yoda Expression "".equals(myString) since then you don't need to pre-test myString for null.
Else you could use myString.isEmpty().
Related
This question already has answers here:
How do you check if a string is not equal to an object? [duplicate]
(2 answers)
Closed 2 years ago.
if (correctAnswer.equals(userChoice.toLowerCase())) {
System.out.println("Your have provided the correct answer. Well done!");
Where I have .equals above as a String operation, is there a .notequals equivalent for it in Java?
You can use negation operator ! to reverse result of equals method like
if (!correctAnswer.equals(userChoice.toLowerCase()))
This question already has answers here:
How do I compare strings in Java?
(23 answers)
Why doesn’t == work on String? [duplicate]
(7 answers)
Closed 2 years ago.
I'm relatively new to Java so I'm kind of lost here. Is it wrong when you are trying to compare two strings just use the identical symbol "==" instead of using a method for checking if two strings are identical. Because for what I have tried the first option doesn't work and I'm very curious on the reason behing it
In java when you use String, you work with reference.
String one = "one";
String two = "two";
if(one == two)
// true if references `one` and `two` point to the same object
if(one.equals(two))
// true if strings `one` and `two` are equals (it could be to different objects)
This question already has answers here:
String.equals versus == [duplicate]
(20 answers)
How do I compare strings in Java?
(23 answers)
Closed 8 years ago.
Can someone explain me on how String class behaves in memory management in java.
I have lately heard about string comparison. how does two string with == operator and equals method differ.
example:
String str1 = "Hello";
String str2 = "Hello";
String str3 = new String("Hello");
any suggestions on case 1 AND case3?
== in Java compares the references of the 2 string objects, and not the contents. The equals methods does is the one that checks the content.
However, due due string interning, I believe that in the case that you listed, str1 == str2 withh be true because there is a single instance of that string literal stored in memory.
This question already has answers here:
How do I compare strings in Java?
(23 answers)
Closed 9 years ago.
My program is using the following code
String mobile="";
if(mobile!="")
System.out.println("++++++");
System.out.println("------");
But if statement always set true. how it is possible? how to correct the code to get false for if condition?
try this way
if(!(mobile.equals("")))
there are difference between == and .equals()
As whoAmI has suggested its better to
if(!("".equals(mobile)))
because it can handle mobile as null
you can't use "!=" on strings. This only compares the references of the strings. If you want to compare the content of the strings you need to use equals
if(!("".equals(mobile)))
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
How do I compare strings in Java?
I'm new to Java. And I've following problem:
string s = "someword";
if (s == "someword")
// do something
Sometimes doesn't work for me. Don't know why.
Thanks for responds.
In Java == compare reference. Use .equals() for compare value.
Duplication of this: How do I compare strings in Java?