Perl The syntax format is as follows: Execute the above program, and the output is as follows:
foreach
loop is used to iterate over the value of a list or collection variable. 5.22.1. Grammar #
foreach var (list) {
...
}
5.22.2. Flow chart #
Example #
#!/usr/bin/perl@list=(2,12,36,42,51);# executeforeach
circulateforeach$a(@list){print"a's value is:$a\\n";}
The value of a is: 2
The value of a is: 12
The value of a is: 36
The value of a is: 42
The value of a is: 51
Principles, Technologies, and Methods of Geographic Information Systems 102
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.