accessing array elements in perl

I. Data Types(Data type): Perl has four data types: Scalar (variable), Scalar Array (Array), Hash Array (Hash), and References (pointer ), it seems to be rare, but it is more than enough to use it. Especially when writing Perl programs, you do not

one. DataType (data type ):Perl's data types are roughly four: Scalar (variables), Scalar Array (array), hash array (hash), References (pointer), but they seem to be small but more than sufficient. In particular, you can write a Perl program without

Perl Arraysa Perl array is a list variable that stores scalar values, and variables can be of different types. array variables begin with @. Access array elements are read using the $ + variable name + [index value] format. 1. Creating an array1.

1. List and array. The list mentioned in this book is a data structure. array is the data type used to store the list in Perl. In most cases, these two words can be exchanged, meaning the same. Unlike C, the Perl array does not need to define the

One, List A list is a sequence of values enclosed in parentheses that can be any value or NULL, such as: (1, 5.3, "Hello", 2), empty list: ().Note: A list containing only one numeric value (for example: (43.2)) is different from the value itself

1. Length of the array: If you assign an array variable to a scalar variable, the length of the array is assigned to the scalar variable: $ A = @ array; # The length of the array @ array is stored in the scalar variable $ A, that is, the number of

One, what is Perl Hash A hash is a data structure, and a similar array, that can be stored in or retrieved from a value. However, unlike arrays, the index is not a number, but a name. That is, the index (here, we call it key) is not a number but an

Perl Learning 5 Hash, perllearninghash [This article is original. Do not reprint it without permission] Hash is a data structure. It is similar to an array in that it can accommodate any number of values and can be used as needed. The difference

Reference/pointers in the 12th chapter PERL5by FlamephoenixI. INTRODUCTION of citationIi. use of referencesThird, use the backslash (\) operatorIv. References and ArraysV. Multidimensional arraysVi. references to sub-programsSub-Program templatesVii.

I. file input/output functions 1. Basic I/O functions Open: Allow programs to access files Close: Terminate File Access Print: file write string Write: Write the formatting information to the file. Printf: format the string and output it to the