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If null is compared with null what is the result-true or false or null or unknown?
Wiki User
∙ 14y ago
You mean SQL?
NULL = anything IS NULL
NULL <> anything IS NULL
...
NULL IS NULL = TRUE
NULL IS NOT NULL = FALSE
Wiki User
∙ 14y ago
Alf Newman
Gary Michael Null (born January 6, 1945) is an American talk radio host and author who advocates for pseudoscientific alternative medicine and produces a line of questionable dietary supplements.
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Null in programming?
in Russian Null means zero. in some languages Null is a macro for zero. in others Null is a single-tone object which referes to the value Null and thus could be compared to other values. Null has many names from nill Nill nil in diffrent languages. most of the time, Null is used to indicate, no value is set to a variable.
Are true false and null Java keywords?
True and false are literals(special built-in value) in java and cannot be used as keywords.
Two Binary Trees are similar if they are both empty or if they are both non-empty and left and right sub trees are similar Write an algorithm to determine if two Binary Trees are similar?
/* Given two trees, return true if they are structurally identical. */ int sameTree(struct node* a, struct node* b) { // 1. both empty -> true if (a==NULL && b==NULL) return(true); // 2. both non-empty -> compare them else if (a!=NULL && b!=NULL) { return(sameTree(a->left, b->left) && sameTree(a->right, b->right) ); } // 3. one empty, one not -> false else return(false); }
How can i check a null at the end of an character array in java?
A character array, by nature, is a primitive-type data array. It can't contain a null value. You cannot cast a char as a null. char[] charArray = {'1','2','s',null}; //this doesn't compile. However, if you have an array of Character objects, then it's possible. Character[] charArray = {'1','2','s',null}; //this DOES compile A proposed algorithm is to initialize a test boolean as false, then use a for loop to iterate through the array. Set the flag to true (and break the loop) based upon whether one of the objects you run into is null. What you do from there is up to what the rest of your code says.
C plus plus program of periodic table?
The Periodic Table Of Elements has a well defined order. The layout can be emulated easily since the arrangement is quite logical.The first step would be to define a struct containing the following members as a minimum:- atomic number (int - number of protons in its nucleus)- symbol (char* - short form of the element name)- name (char* - long form of the element name)i.e.:struct elementinfo {int atomicnumber;char *symbol, *name;};Other members can be added as your program develops.The next step is to arrange the table itself. If you're using Win32 or another graphical system, it's a matter of drawing a box (Win32 would require a MoveToEx() call and four LineTo() calls) and TextOut() (or a related function) for the atomic number and element symbol (centered horizontally and aligned top and bottom respectively).Including conio.h or curses.h would give you the ability to position the cursor and even change the text color, allowing for an alternate "graphical" method.To keep things simple, storing the elements in an array would require something akin to the following:struct elementinfo elementlist[]={{1, "H", "Helium"}, {0, NULL, NULL}, {0, NULL, NULL},{0, NULL, NULL}, {0, NULL, NULL}, {0, NULL, NULL},{0, NULL, NULL}, {0, NULL, NULL}, {0, NULL, NULL},{0, NULL, NULL}, {0, NULL, NULL}, {0, NULL, NULL},{0, NULL, NULL}, {0, NULL, NULL}, {0, NULL, NULL},{0, NULL, NULL}, {0, NULL, NULL}, {2, "He", "Helium"},{-1, NULL, NULL},{3, "Li", "Lithium"}, {4, "Be", "Beryllium"}, {0, NULL, NULL},{0, NULL, NULL}, {0, NULL, NULL}, {0, NULL, NULL},{0, NULL, NULL}, {0, NULL, NULL}, {0, NULL, NULL},{0, NULL, NULL}, {0, NULL, NULL}, {0, NULL, NULL},{5, "B", "Boron"}, {6, "C", "Carbon"}, {7, "N", "Nitrogen"},{8, "O", "Oxygen"}, {9, "F", "Fluorine"}, {10, "Ne", "Neon"},{-1, NULL, NULL},...{-2, NULL, NULL}};In the above array, {0, NULL, NULL} represents a blank displayed for that particular cell, and {-1, NULL, NULL} represents a newline. The {-2, NULL, NULL} signifies the end of the table. The following for() loop would wrap around your display code like so:for (count=0; elementlist[count].atomicnumber!=-2; count++) {if elementlist[count].atomicnumber==-1) {// jump to next line of elements}else {// display current element}}Drawing this graphically, you'd have to keep track of the current cursor (X, Y) position.If you are sending this to stdout or another text stream (i.e. text file), you could draw each line, referencing the array of elements as you go. The list of elements would have to be stored in a nested array: the outermost array contains each line of elements in an array. This would do away with the {-1, NULL, NULL} terminating each line of elements.Extending this code to use classes would be relatively simple, but might only make sense if you were drawing this graphically storing each element as an object.The Lanthanides and Actinides, since they're displayed separately from the main table, would probably have to be stored separately for sake of convenience.Also, as laboratories continue to synthesize (or, on the rare chance, discover) new elements, the layout of the table may change (even drastically) to suit. Thus, the code would have to be altered accordingly.See the related links below for more ideas on how to design a program that displays the Periodic Table of Elements.(Note: Code originally posted was copyrighted. Added to related links.)
What is a Type II Error - a false-negative error?
Falling to reject (accepting) a false null hypothesis.
Types of Hypothesis and definition?
In formal design and analysis of experiments there are but two types of hypotheses: null and alternative. And one might argue there really is only one because when the null is properly defined, the alternative is automatically properly defined. The null hypothesis is a testable statement of conjecture. The purpose of the null hypothesis is to set the measurable goal for the experiment that follows to show that the null is not false. If the results of the experiment do not show that then the alternative hypothesis is by definition not false. Simple Example: Null: It's raining outside. Alt: It's NOT raining outside. NOTE: The NOT reverses the logic of the null. The experiment...walk outside. The test...if I get wet, the Null is not false. If I don't get wet, the alternative is not false. NOTE: I must have an experiment to test the hypothesis. Without a test it's not a valid hypothesis.
What is a beta error?
A beta error is another term for a type II error, an instance of accepting the null hypothesis when the null hypothesis is false.
What are the various cases where use of a NULL value would be appropriate?
Optional data fields: NULL can be used to indicate that certain fields in a database can have no value assigned to them. Unknown data: NULL can be used to represent missing or unknown information. Default values: NULL can be used as a default value for a field until a proper value is provided. Uninitialized variables: In programming, NULL can be used to indicate that a variable has not been assigned a value yet.
Null in programming?
in Russian Null means zero. in some languages Null is a macro for zero. in others Null is a single-tone object which referes to the value Null and thus could be compared to other values. Null has many names from nill Nill nil in diffrent languages. most of the time, Null is used to indicate, no value is set to a variable.
What is Hypothesis Testing of Power?
The probability of correctly detecting a false null hypothesis.
What is Type I Error - a false-positive error?
Rejecting a true null hypothesis.
Explain the principle of null-method of measurement?
The null method is used in measuring the unknown EMF of batteries. The method is about using a potentiometer circuit with the battery of a known and then an unknown EMF connected to it one after the other and locating, in each case, the position of the 'null point'; the point on the potentiometer circuit where the current through the battery is zero.
If the null hypothesis is true and the researchers do not reject it then a correct decision has been made?
True because the point of the hypothesis test is to figure out the probability of the null hypothesis being true or false. If it is tested and it is true, then you do not reject but you reject it, when it is false.
Are true false and null Java keywords?
True and false are literals(special built-in value) in java and cannot be used as keywords.
A NULL value is treated as a blank or 0 1.true 2.false?
true
What is Hypothesis Testing of Type II Error?
Failing to reject a false null hypothesis.
