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Putting it very simply a null value is empty and a not null value contains something.
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Difference between void pointer and null pointer?
A Null pointer has the value 0. void pointer is a generic pointer introduced by ANSI. Before ANSI, char pointers are used as generic pointer. Generic pointer can hold the address of any data type. Pointers point to a memory address, and data can be stored at that address.
What is the use of null in database?
Sometimes, a particular field in a database row has a value that is either unknown or undefined. An example might be the termination date of an employee who is still employed by the company. A date field would not accept any value that was not a valid date but no date has been determined for the field as yet. A null would indicate that.
Entity integrity constraint?
The entity integrity constraint states that no primary key value can be null. This is because the primary key value is used to identify individual tuples in a relation. Having null value for the primary key implies that we cannot identify some tuples. This also specifies that there may not be any duplicate entries in primary key column key row.
Default value for instance variable?
Depending on the language you are using the default of an instance variable can be '0', 0, null, empty, '', or have a random number.
Difference between right join and inner join?
Hi, Natural Join: It is combination or combined result of all the columns in the two tables. It will return all rows of the first table with respect to the second table. Inner Join: This join will work unless if any of the column name shall besxame in two tables
What is the difference between equals 0 and equals NULL?
NULL is for pointers, 0, for numbers
What is the difference between 0 and null?
Nothing - 0, Zero and null are the same things
What is the difference between null in c and in oracle?
A NULL in C is a pointer with 0 value, which cannot be a valid address. A null in Oracle is the condition of not having a value, such as a field in a row being null, meaning that it does not have a value. This is not the same as zero - zero and null are two different things. Note, however, that Oracle does not differentiate between a null and a zero length string. This was an error in non-ANSI implementation made many years ago, but it has persisted because fixing it would impact too much "running" code.
How does the difference between fe and fo influence the outcome of a chi-square test?
The larger the difference, the larger the value of chi-square and the greater the likelihood of rejecting the null hypothesis
What is the difference between zero vector and null vector?
They are the same.
What is the difference between a null hypothesis and a research hypothesis?
The null hypothesis is the default hypothesis. It is the hypothesis that there is no difference between the control group and the treatment group. The research hypothesis proposes that there is a significant difference between the control group and the treatment group.
Difference between p value and level of significance?
P- value is the probability that the given null hypothesis is true and the level of significance is the chance in a hundred or thousand off occurence of an event i an outcome
How is the null hypothesis of the independent samples t test verbalized?
The null hypothesis of the independent samples t-test is verbalized by either accepting or rejecting it due to the value of the t-test. If the value is less than 0.05 it is accepted and greater than 0.05 is rejecting it.
What is the difference between array and string of array?
When we declare an array of characters it has to be terminated by the NULL , but termination by NULL in case of string is automatic.
What is the difference between two source hypothesis and two gospel hypothesis?
null
What is the difference between null pointer ASCII null character and null string?
A null pointer is a pointer which does not point to any valid memory location, and usually contains the binary value "0" to represent this (this is language dependent). The ASCII null character is a character-sized zero value (in ASCII, it is an unsigned byte with a value of 0), and typically represents the end of a string (esp. as in C and C++). A null string is one that is zero characters of usable string data; in a length-based string, this means the length parameter is set to 0, and in an ASCII null-terminated string, means the first character is set to 0.
What is the difference between an array shift and unsetting a variable in PHP?
By shifting the values in an array, you are moving a key's value to the previous key. The very first key's value is obliterated. By shifting all values in the array, all keys will have a value of NULL. Unsetting a variable is entirely different -- performing a variable unsetting causes the variable to have a value of NULL, as if it was never set.
