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.
Related
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:
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().
This question already has answers here:
How many String objects will be created
(3 answers)
Closed 5 years ago.
I have following two lines in Java code :
String str = new String("My place")
String str1 = new String("My place")
It is clear that new String("My place") creates two object,one due to interning and another due to new but i am confused as here the argument is having same literal so whether same interned object is being used by str1 resulting in 3 objects or different resulting in 4 objects
Interning of string literals is automatic in Java, so the same interned object will be used in both constructors, so there will be three objects, not four.
same interned object will be used by str1 resulting in 3 objects , try to undertnad using equals methods
This question already has answers here:
How do I compare strings in Java?
(23 answers)
Closed 7 years ago.
I wrote the following JAVA code in eclipse,
String s1 = "a";
String s2 = s1 + "b";
String s3 = "a" + "b";
System.out.println(s2 == "ab");
System.out.println(s3 == "ab");
The output is
false
true
why the result is like that, can some explain it to me?
as I understand, both of them should be true.
We do not use == to compare Strings in java. It will compare the object references to system memory.
You have several options:
equals
equalsIgnoreCase
matches (Regex)
In your example you defined two Strings. Both will live in different memory locations. == compares only the reference to that location and will find that it is not the same, since you are calling it on two different Strings.
The second comparison is true because java only added one "ab" to memory, hence it will point to the same location. See: java string pool
This question already has answers here:
How do I compare strings in Java?
(23 answers)
Closed 8 years ago.
So I understand that the == checks for equality in the reference number (the address of objects in memory). And the .equals() checks for the content of the objects.
String s = "test";
String s2 = "test";
I'm creating two different string objects but yet, I get the following:
s == s2; //true, I dont know why, aren't s and s2 two different objects with
different internal values
s.equals(s2); //true, which I understand
aren't s and s2 two different objects
No. s and s2 refer to the same Object that has been interned in the String pool