Perl continue blocks are usually executed before the conditional statement is evaluated again. The continue statement can be used in while and foreach loops. Syntax con in while loop
The Perl next statement is used to stop execution of the statements starting from the next statement of the next statement to the end identifier of the loop body, transfer to the execution of the continue statement block, and then return to the beginning
The Perl language allows the use of a loop within another loop. Here are a few examples to illustrate this concept. Grammar Nested for loop statement syntax: for(init; condition; inc
Perl is a weakly typed language, so variables do not need to be typed; the Perl interpreter automatically selects a matching type based on context. Perl has three basic data types: scalar, array, and hash. The following are these three
There are two different implementations of object-oriented programming in Perl: one is based on anonymous hash tables. The essence of each object instance is a reference pointing to an anonymous hash table. In this anonymous hash table, all instance attri
Socket is also called "socket". Applications usually send requests to the network or respond to network requests through "socket", so that hosts or processes on a computer can communicate. In this chapter we receive Perl for everyone
Regular expression (regular expression) describes a string matching pattern, which can be used to check whether a string contains a certain substring, replace the matching substring, or extract from a string that meets a certain condition.
During the running of the program, you will always encounter various errors, such as opening a file that does not exist. If an error occurs during the running of the program, it will stop. We need to use some detection methods to avoid errors and prevent
Perl uses a variable called a file handle type to manipulate files. Reading or writing data from a file requires a file handle. A file handle is the name of an I/O connection. Perl
Perl is a very powerful text data processing language. In Perl, you can use format to define a template, and then use write to output data according to the specified template. Perl formatting definitions
Perl subroutines are also user-defined functions. A Perl subroutine is a separated piece of code that performs a specific task, which can reduce repetitive code and make the program easier to read. Perl subroutines can appear anywhere in a program
An operator is a symbol that tells the compiler to perform a specific mathematical or logical operation, such as: 3+2=5. The Perl language has a wealth of built-in operators. Let’s take a look at some of the commonly used ones: arithmetic operators compar
Sometimes, we may need to execute the same block of code multiple times. Normally, statements are executed sequentially: the first statement in the function is executed first, followed by the second statement, and so on. Programming languages provide mo
A hash is a collection of key/value pairs. Hash variables in Perl start with a percent sign (%). Access hash element format: ${key}. Here is a simple hash example: Example #!/usr/b
A scalar is a simple unit of data. A scalar can be an integer, a floating point number, a character, a string, a paragraph, or a complete web page. The following example demonstrates a simple application of scalars: Example#!/usr/bin/perl $
