Preface:
Definition:The concept of singular and plural: Scalar is a single thing. perl uses scalar (the simplest data type in perl) to call a single thing. For most scalar values, it is either a number or a string composed of characters (perl does
1. Initialization of arrays(1) Create an array with arrayA: $products = array (' tires ', ' oil ', ' Spark plugs ');Array () is actually a language structure, not a function
B: Initializing the related array$prices = Array (' Tires ' =>100, ' oil ' =
1.?? operator (NULL merge operator)
$a = $_get[' A ']?? 1;
It is equivalent to:
$a = empty ($_get[' a '])? 1: $_get[' a '];
We know that ternary operators can be used in this way:
$a?: 1
But this is based on the premise that the $a has been defined.
Learning Perl 4ed Reading Notes
Chapter2 scalar data1. Numbers. All data (INT, float) is of the double type in Perl. Of course, sometimes Perl also uses integer to represent int internally, because this can improve the running speed of the program,
Introduction to Perl Syntax Perl operators
1.Perl operator
1.1 Arithmetic operators
Perl is very different in variables and data paradigms and C. However, its operator and C are almost identical, except for the example conversion operator type of
Let's take a look at scalar operators. scalar can be divided into two types: Numbers and strings. In Perl, these two types of data can be converted to each other, but operations are different.
The following describes the numeric operators:
There
The examples in this article describe the PHP7 scalar type declare usage. Share to everyone for your reference, specific as follows:
In order to improve the execution efficiency, the PHP7 of scalar type (Boolean, floating-point, Integer, character)
I found a good post:
(The answer is very professional)
Hey all.
I'm a complete beginner in assembly and have chosen NASM to work my way up. but I have a problem with the pseudo-instruction set. more precisely, I don't understand how the expressions
In this section, we discuss the semantic checking of unary operator expressions, as shown in their associated code 4.2.35. For the "pre-Gaga" and "pre-decrement" operators, we take the same strategy as "post-Gaga" and "post-decrement", converting--a
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