compare « Integer « Java Data Type Q&A

1. How do I compare strings in Java?

I've been using the "==" operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed ...

2. What's wrong with using == to compare floats in Java?

According to this java.sun page == is the equality comparison operator for floating point numbers in Java. However, when I type this code:


3. How do I compare two Integers?

This sounds like a stupid question, but I'm kinda stuck here. I have to compare two Integer (not int). How do I compare them?

Integer x = ...
Integer y = ...
I can think ...

4. Java: String compare library that returns diff count as an int?

Does a library or even standard API call exist that allows me to diff two strings and get the number of diff chars as an int? I wouldn't mind other features, ...

5. Comparison between variables pointing to same Integer object

The ourput of current program is "Strange". But the both the variables share the same reference why are second and thrid comparison not true.

Integer a;
Integer b;
a = new Integer(2);
b = a;
if(b ...

6. Why comparing Integer with int can throw NullPointerException in Java?

It was very confusing to me to observe this situation:

Integer i = null;
String str = null;

if (i == null) {   //Nothing happens
   ...     ...

7. Compare int and Object in Java

I have the following code:

Object obj = 3;
//obj.equals(3); // so is this true?
Does obj equal to 3?

8. Comparing Integer objects vs int

I fixed an endless loop by changing Integer to int in the following:

public class IntTest {
    public static void main(String[] args) {

9. Compare two strings of ints in java

Hi I have two Strings that contain numbers and I want to see if the string two contains the same numbers as string one is there any way and they are ...

10. comparison if statment should be called twice but it is only called once when comparing an Integer

I have a function that takes a Integer array and a boolean array. If the value in the Integer array is the highest value and the boolean array is true, ...

11. Initializing and comparing integers

Besides the syntax, is there a difference (performance, semantics, etc.) between these two ways to initialize Integers?

Integer i = new Integer(10);
Integer i = Integer.valueOf(10);
And is there a difference between these two ...

12. How come Java's Integer class does not have compare() method?

Double has for comparing two double primitives. Why doesn't Integer have one? I understand it's some trivial amount of code to write, but asking out of curiosity. Edit: I realize both Integer ...

13. compare two Integer

Possible Duplicate:
Wrapper class and == operator
Hi when I am comparing Integer with == I have some problem so can you explain me why second ...

14. { int == nulltype } vs. { Integer == nulltype }

Why java complains about

// int i;
if( i == null ){  }
and not about
// Integer i;
if( i == null ){  }

15. Comparing three integer values

Is something like this ever possible?

if(a == b == c)
or is
if((a== b) && (b == c)) 
is the only way? or what is the coolest way to do that?

16. Compare Mutiple Integers and find largest in java

I am kind of new to java, and I am making a MAbovePixel Generator. Right now my idea is that the very top pixels, and the very right pixels are blue, ...

17. Why doesn't my compare work between char and int in Java?

Possible Duplicate:
Comparing Character, Integer and similar types in Java: Use equals or ==?
char c = data.charAt(4);
System.out.println(c + "-" + s);
if (c == s) { ...

18. a simple int comparison causing issue

I've got the following code:

 int bookingType=0;

        DateTime startx = new DateTime(startDate.getTime());

19. Comparing integers

I need to compare a 'rank' score of speech competitors in my program the following code alphabatises the names of the people for ( int sc=1; sc

20. How to compare String and int?

Hi, How do we write a code that does this: a) if the user key-in any number from 0 to 100, it will loop and perform some task. b) if the user key-in any number less than 0 or more than 100, it will prompt the user to re-enter the correct number. c) if the user type-in "quit", it will exit ...

21. Compare String with Integer

Well, it is like a question of comparing an orange and an apple. You can't compare them if you don't give specific criteria. If you want to compare their integer values, then you should convert the string to integer before comparing as you did with proper error handling (i.e. when the string is not an integer). If you want to compare ...

22. Comparing Integer and Long

ALL compile ok, and give the right result. So why is equality "==" incomparable, but >, <, >=, <= are comparable? When you compare with the == operator, the compiler is assuming that you are trying to compare whether the references are pointing to the same instance. And since there is no way that a Long reference can point to something ...

23. Comparing ints

26. How to compare the String with integer

27. unable to compare strings and ints

Hi everyone. I'm trying to compare ints and strings for a networked java application, System.out.println("here") won't print, evern when todo = 1. At a loss. Rob. Java Code: public static void NetLoad(int todo) { int x[] = new int[4]; int y[] = new int[4]; Ships.clear(); String[] sArray = new String[3]; System.out.println("todo = " + todo); try { System.out.println("start cc"); if (todo ...

28. Integer Comparison, Outputting Largest Integer Not Working

I'm writing a Java program to take three integers and output the smallest, largest, sum, and average. Everything works except for finding the highest integer. If I set number1 to 1 and number2 to 2 and number3 to 3, the program outputs 2 as largest. If I do it in this order 3, 1, 2, it puts out 3 as the ...

29. Comparing String to Int variable

30. comparing equality between 2 strings using '=='

Compile-time strings are allocated from the constants pool - so, in your example, both 'a' and 'b' really are references to the same entity, and '==' works. In the second case, you're allocating new objects, each of which has the content - but they're different entities, and == returns false. Does that help? Grant

31. comparing long to int

32. the detail about compare to Integers.

In first case, both n1 and n2 refer to the same Integer instance. I don't know how ++ operator behaves in conjunction with autoboxing, but Integer objects are immutable (just like String) In second case, n1 and n2 are different instances of integer representing the same value. Therefore == will return false. You should always use the equals method to compare ...

33. Help with comparing integers, I'm completely baffled.

Heh, I just had a meeting where I announced that putting the opening curly on the same line was being added to our coding standards. I figured if the morons who insist on coding java in Vi can have standards on no tabs and 80 chr hard line length limits then I could sneak one in that is actually useful and ...

34. Integer comparison with null problem

35. STRING vs INTEGER Comparison!

== compares primtives or reference values. When you do str1 == str2 on reference variables, the == is true if and only if both references point to the same object, or both are null (pointing to no object). If you want to compare objects' states, (including Strings' contents), use the equals method. This method will compare the objects' "contents" by whatever ...

36. how to compare String and integer

just wanna ask some help guys, how to compare String data type from int and vice versa. im doing a program that i will input a number and convert it in words. my problem is how can i make it an error when the input is a letter. pls email me at thankzzzz

37. comparing 2 Integer objects...

Hi, For object comparision use equals() method instead of ==. == compares whether the 2 references are equal or not. In your case, There is one intresting thing with == comparision of wrapper objects. It is for Integer,Long,Short,Char if the value you assign to wrapper class is in between -128 <= object value <=127, then == comparision results in true. and ...

38. comparing two Integer lists

39. Comparing integer ranges in java

40. comparing a single int to more than one int value?

Well, think about it. In if you nest as deep and as wide as you want with parens, and you have the operators >, <, ==, and != as well as the operators && and ||, as well as compareTo() and equals() methods for objects, as well as boolean objects. Experiment abit.

41. String & Integer Comparison problem!

42. Integer Comparison Question

43. Suspicious comparison of Integer references

earlier message was: This method compares two reference values using the == or != operator, where the correct way to compare instances of this type is generally with the equals() method. It is possible to create distinct instances that are equal but do not compare as == since they are different objects. Examples of classes which should generally not be compared ...