Questions tagged as 'null'

Tagged questions
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What is the difference between NULL and null?

Is there any difference between NULL (written in upper case) and null (written in lowercase) in PHP? I know I can use both types, but is there any naming rule for these words?     
asked by 19.09.2017 / 23:05
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Difference of null and other proposition using this null object

If I have a code, for example: if(window!=null && window.isOpen()){ //todo } If window is null , will it still try to call the second proposition or not check anymore? Because if it tries to call, then it will give...
asked by 25.08.2016 / 14:06
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How to change null field to return nothing?

In a query has many fields unfilled, I would like to change the null being printed so that nothing appears in the print.     
asked by 18.05.2016 / 21:41
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Variable declaration with! at the end Swift 3

Why do some variable declarations in Swift3 add an exclamation point (!)? For example: var _nome: String! var _idade: Double! What does this entail? When should it be used?     
asked by 17.02.2017 / 19:33
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NULL value in database x performance

I have always used a MySQL database for small projects and I never cared about the option "NULL when it is empty", that is, it was blank. Now I'm designing a large system, I would like to know the concept of using NULL value when the f...
asked by 21.10.2015 / 19:31
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What is -EPERM in C?

What is the -EPERM , after which compares if the p pointer is null if(p == NULL) return -EPERM ; And I have to put these two libraries. #include <errno.h> #include <stddef.h>     
asked by 23.04.2016 / 17:28
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toString returning Null when it should not

I have the class Aluno . public class Aluno { private String nome; @Override public String toString() { return this.nome; } //metodos getters e setters } Class Vetor public class Vetor { p...
asked by 13.07.2016 / 14:39
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Change value of an array when null

I have a WebService in PHP that returns me a JSON with values from a mySQL database. I need an Array, whenever there is a null value (when = null ), is changed to white ( = "" ). I'm doing it this way, but without success. &l...
asked by 04.11.2014 / 10:44
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How to check Null in a select @Local_Variavel

How to set a default value for a local variable, if the select that should "set" it returns NULL ? For example: DECLARE @Minha_Var VARCHAR(70) SELECT @Minha_Var = Nome FROM CLIENTES WHERE Id = 10 This query can return NULL , ri...
asked by 25.10.2017 / 12:06
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How to handle Null records? In the bank or app? (java & mysql)

I'm integrating a legacy (MySQL) database with a new module (Java - this problem-giving object is a bean) that I'm developing. I have a method that does a select and returns some results that possibly have some null data and thi...
asked by 25.04.2018 / 22:28