mean by null

Null Pointer Vulnerability Protection Technology-PreliminaryIn the security history, the number of vulnerabilities and attacks caused by null pointers is numerous. However, due to its requirements on the programming capability of the caller, the

In some shell scripts, especially in crontab scripts, >/dev/null2>&1 is often seen as such. In fact, this is very good understanding. We explain in two parts. 1. >/dev/null Everyone knows that ">" (Right angle bracket) in the Unix/linux shell means

When creating table, we often encounter such a statement, for example, corpname nvarchar (10) Collate chinese_prc_ci_as null. What does it mean? Take a look at the following:   Syntax Collate ::={Windows_collation_name} | {SQL

Many people usually think that the null value is the same as the blank value or the 0 value. At least I thought so before today. In fact, the null value is not the same as the blank value or the 0 value. Null indicates that the value is unknown.

Before learning and using guava optional, let's take a look at null in Java. Because, only by having a deep understanding of null, can we gain a deeper understanding of guava's optional design and usage in elegance and simplicity. Null

In fact, there is nothing to say about this problem, today's optimization encountered an SQL statement, because it is more interesting, so I intercepted, simplified the SQL statement, to show you, as shown belowDECLARE @bamboo_Code varchar (3);Set

What does "g" in a regular expression mean by the use of the attachment parameter g? What does "/g" in the regular expression (/[^ 0-9]/g, '') mean ?" This problem also aims to make it easier for you to have a more comprehensive and profound

"Editor's note" in the 90 's, the linux+apache+mysql+php architecture was rage until now, still the basic architecture of many WEB applications. However, with the change of demand and the explosion of data flow, LAMP has inevitably gone down the

Summary Spare time to learn groovy and Scala running on the JVM, discovering that their handling of NULL is much more discreet than earlier versions of Java. In Java8, Optional gives a very elegant solution for null processing of functional

I. Wild pointer The "wild pointer" is not a NULL pointer, but a pointer to the "junk" memory. There are two main causes of "wild pointer: (1) pointer variables are not initialized. When a pointer variable is created, it does not automatically become