Why does containsAll return false? [closed] - java

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Why does this code evaluate to false?
code:
String[] a = {"donald,duck"};
String[] b = {"duck,donald"};
System.out.println(Arrays.asList(a).containsAll(Arrays.asList(b)));
output:
false
From the docs:
boolean containsAll(Collection c)
Returns true if this list contains all of the elements of the specified collection.
Update: Realized the flaw as soon as the first answer ticked in. I'll go and sit in the corner for a while now, thanks. *equips hat of shame*

Since "donald,duck".equals("duck,donald") is false, hence the result. You've 2 arrays with 1 elements each.

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I want to replace ALL double spaces with single spaces, including those after a period [closed]

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Closed 1 year ago.
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I have this code:
item.replaceAll("\\s+", " ")
and this is the string
"The census request file for completion has been attached.  In addition, the attached Client Checklist "
It doesn't work: double space remains after the period, so ".  If" is unchanged.
I don't understand WHY!?
Since String.replaceAll() method is not an in-place operation, you should write like this:
item = item.replaceAll("\\s+", " ")

How to fix '(' or '[' expected [closed]

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Closed 2 years ago.
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I get this error when I try to do an Onclicklistener to my customInfoWndow
The code for that is specifically this:
(GoogleMap.OnInfoWindowClickListener((new GoogleMap.OnInfoWindowClickListener))
How may I solve this error.
Thanks a lot!
You have a new keyword, so you're constructing an object. If the constructor takes no parameters, you must put empty braces anyway:
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Random.nextInt seems wrong from a book [closed]

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Closed 4 years ago.
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It's a block of code for random verification code in a Servlet book.
the underlined part must be a number of 30+?
but the intention is one of those chars above
Pic
NextInt method only has one parameter which is the max number (exclusive)?
So is it a mistake in the book?
nextInt(int) returns a [pseudo]random number between 0 and the parameter passed to it, exclusive. Thus, if you pass a length of an array, you'd get a random valid index from the array, which you can then use to pick a random element from it, as this code does.

How do I check in JAVA if a string is not equal to? [closed]

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How do I check in Java if a string is not equal to "ABC"?
I know that to check if it is equal we can type string.equals("ABC") but how do I do it when I want to check if it is not equal?
Simply negate the result of equals:
!string.equals("ABC")
String.equals returns a boolean value, to get the inverse of any boolean value, use the ! operator:
boolean t = true; // t will be true
boolean f = !t; // f will be false
Negate the returning value from string.equals(TestString):
!string.equals("ABC")
You better have a look at Logical Operators in Java
You can simply write it like this.
!string.equals("ABC")

Scientific Notation as a Double java Android [closed]

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Closed 8 years ago.
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If this was a string and it was parsed as a double. Would java be able to process this as the expected value or would I need to change the format of these numbers? Would I need to remove the "+" or change e to "E"?
1.3870574e+01
The string parsed to a double just fine on my system.
See Double.valueOf(String str)

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