5. Perl

  • 5.1. Perl tutorial

    Perl is the abbreviation of Practical Extraction and Report Language and can be translated into “practical report extract...
    2025-10-25 13:33:03 UTC
  • 5.2. Perl introduction

    Perl, a feature-rich computer programming language, runs on more than 100 computer platforms and is suitable for a wide rang...
    2025-10-25 13:33:03 UTC
  • 5.3. Perl environment installation

    Before we can start learning the Perl language, we need to install the Perl execution environment. Perl can run on the fol...
    2025-10-25 13:33:02 UTC
  • 5.4. Perl basic syntax

    Perl borrows the features of C, sed, awk, shell scripts, and many other programming languages, and the syntax is somewhat si...
    2025-10-25 13:33:01 UTC
  • 5.5. Perl data type

    Perl is a weakly typed language, so variables do not need to specify a type,and the Perl interpreter automatically selects t...
    2025-10-25 13:33:06 UTC
  • 5.6. Perl variable

    A variable is data stored in memory, and creating a variable opens up a space in memory. The interpreter determines the st...
    2025-10-25 13:33:06 UTC
  • 5.7. Perl scalar

    Scalar is a simple data unit. Scalars can be an integer, floating point, character, string, paragraph, or a complete web p...
    2025-10-25 13:33:07 UTC
  • 5.8. Perl array

    Perl array is a list variable that stores scalar values, and variables can be of different types. Array variables to ...
    2025-10-25 13:33:06 UTC
  • 5.9. Perl hash

    The hash is key/value that’s right Gather. Perl hash variable in the starts with the percent sign (%). Access th...
    2025-10-25 13:33:01 UTC
  • 5.10. Perl conditional statement

    Perl conditional statement is the result of the execution of one or more statements True or False to determine t...
    2025-10-25 13:33:04 UTC
  • 5.11. Perl IF statement

    Perl if statement consists of a Boolean expression followed by one or more statements. 5.11.1. Grammar # The sy...
    2025-10-25 13:33:04 UTC
  • 5.12. Perl IF…ELSE statement

    One if statement can be followed by an optional else statement else statement in a Boolean expression false ...
    2025-10-25 13:33:01 UTC
  • 5.13. Perl IF…ELSIF statement

    One if statement can be followed by an optional elsif statement, and then follow another else statement. This ...
    2025-10-25 13:33:04 UTC
  • 5.14. Perl UNLESS statement

    One unless statement consists of a Boolean expression followed by oneor more statements. 5.14.1. Grammar # The ...
    2025-10-25 13:33:06 UTC
  • 5.15. Perl UNLESS…ELSE statement

    One unless statement can be followed by an optional else statement else statement in a Boolean expression true...
    2025-10-25 13:33:00 UTC
  • 5.16. Perl UNLESS…ELSIF statement

    One unless statement can be followed by an optional elsif statement, and then follow another else statement. T...
    2025-10-25 13:33:04 UTC

Principles, Technologies, and Methods of Geographic Information Systems

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In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.