- What does != NULL mean?
- IS NULL allowed in ArrayList?
- How do you check if a BigDecimal is greater than zero?
- Why use BigDecimal instead of double?
- How do I declare BigDecimal?
- How do you remove duplicates in ArrayList?
- Which is bigger double or float?
- Will ArrayList allow duplicates?
- IS NULL keyword in Java?
- Are two null values equal?
- How does BigDecimal compare to Java?
- Does HashMap allow duplicates?
- What is difference between double and decimal?
- What is the difference between double and float in Java?
- IS NULL == NULL in Java?
- Is an empty ArrayList null?
- How do I know if my BigInteger is zero?
- Does TreeSet allow duplicates?
What does != NULL mean?
NULL is not a value.
It is literally the absence of a value.
You can’t “equal” NULL.
The operator != does not mean “is not”; it means “is not equal to”..
IS NULL allowed in ArrayList?
An ArrayList explicitly is allowed and able to store null values, because they might be meaningful to your program. And empty list is empty (i.e. doesn’t contain anything, not even null .
How do you check if a BigDecimal is greater than zero?
8 Answers. Every object of the Class BigDecimal has a method compareTo you can use to compare it to another BigDecimal. The result of compareTo is then compared > 0 , == 0 or < 0 depending on what you need.
Why use BigDecimal instead of double?
A BigDecimal is an exact way of representing numbers. A Double has a certain precision. Working with doubles of various magnitudes (say d1=1000.0 and d2=0.001 ) could result in the 0.001 being dropped alltogether when summing as the difference in magnitude is so large. With BigDecimal this would not happen.
How do I declare BigDecimal?
Using a BigDecimal implies that you should: Create new BigDecimal variables, using the constructor. In order to add a BigDecimal to another BigDecimal, use add(BigDecimal augend) API method, that returns a BigDecimal whose value is (this + augend), and whose scale is max(this. scale(), augend.
How do you remove duplicates in ArrayList?
Approach:Get the ArrayList with duplicate values.Create a LinkedHashSet from this ArrayList. This will remove the duplicates.Convert this LinkedHashSet back to Arraylist.The second ArrayList contains the elements with duplicates removed.
Which is bigger double or float?
A double is 64 and single precision (float) is 32 bits. The double has a bigger mantissa (the integer bits of the real number). Any inaccuracies will be smaller in the double.
Will ArrayList allow duplicates?
4) Duplicates: ArrayList allows duplicate elements but HashMap doesn’t allow duplicate keys (It does allow duplicate values). 5) Nulls: ArrayList can have any number of null elements. … In HashMap the elements is being fetched by specifying the corresponding key.
IS NULL keyword in Java?
In Java, null is a reserved word for literal values. It seems like a keyword, but actually, it is a literal similar to true and false.
Are two null values equal?
In SQL null is not equal ( = ) to anything—not even to another null . According to the three-valued logic of SQL, the result of null = null is not true but unknown. … With is [not] distinct from SQL also provides a comparison operator that treats two null values as the same.
How does BigDecimal compare to Java?
BigDecimal. compareTo(BigDecimal val) compares the BigDecimal Object with the specified BigDecimal value. Two BigDecimal objects that are equal in value but have a different scale (like 2.0 and 2.00) are considered equal by this method.
Does HashMap allow duplicates?
HashSet vs HashMap HashSet does not allow duplicate elements that means you can not store duplicate values in HashSet. HashMap does not allow duplicate keys however it allows to have duplicate values. … HashMap permits single null key and any number of null values.
What is difference between double and decimal?
Double (aka double): A 64-bit floating-point number. Decimal (aka decimal): A 128-bit floating-point number with a higher precision and a smaller range than Single or Double.
What is the difference between double and float in Java?
Double takes more space but more precise during computation and float takes less space but less precise. According to the IEEE standards, float is a 32 bit representation of a real number while double is a 64 bit representation. In Java programs we normally mostly see the use of double data type.
IS NULL == NULL in Java?
equals(null)) // Which mean null. … When your obj will be null it will throw Null Point Exception. so we should use == if(obj == null) it will compare the references.
Is an empty ArrayList null?
7 Answers. No. An ArrayList can be empty (or with nulls as items) an not be null. It would be considered empty.
How do I know if my BigInteger is zero?
The java. math. BigInteger. signum() method helps us to identify whether a BigInteger is positive or zero or negative.returns -1 when number is negative.returns 0 when number is zero.returns +1 when number is positive.
Does TreeSet allow duplicates?
Features of a TreeSet So, duplicate values are not allowed. Objects in a TreeSet are stored in a sorted and ascending order. TreeSet does not preserve the insertion order of elements but elements are sorted by keys.