Search results
Results from the WOW.Com Content Network
The following list contains syntax examples of how a range of element of an array can be accessed. In the following table: first – the index of the first element in the slice; last – the index of the last element in the slice; end – one more than the index of last element in the slice; len – the length of the slice (= end - first)
Inserting or deleting an element in the middle of the array (linear time) Inserting or deleting an element at the end of the array (constant amortized time) Dynamic arrays benefit from many of the advantages of arrays, including good locality of reference and data cache utilization, compactness (low memory use), and random access. They usually ...
(dot). Array elements are accessed and set with square brackets in both associative arrays and indexed arrays. Curly brackets can be used to access array elements, but not to assign. PHP has three types of comment syntax: /* */ which serves as block comments, and // as well as # which are used for inline comments. [14] Many examples use the ...
Perl 5 has built-in, language-level support for associative arrays. Modern Perl refers to associative arrays as hashes; the term associative array is found in older documentation but is considered somewhat archaic. Perl 5 hashes are flat: keys are strings and values are scalars.
The number of elements in an array can be determined either by evaluating the array in scalar context or with the help of the $# sigil. The latter gives the index of the last element in the array, not the number of elements. The expressions scalar(@array) and ($#array + 1) are equivalent.
In Perl, foreach (which is equivalent to the shorter for) can be used to traverse elements of a list. The expression which denotes the collection to loop over is evaluated in list-context and each item of the resulting list is, in turn, aliased to the loop variable. List literal example:
Perl. Block comments in Perl are considered part of the documentation, and are given the name Plain Old Documentation (POD). Technically, Perl does not have a convention for including block comments in source code, but POD is routinely used as a workaround. PHP. PHP supports standard C/C++ style comments, but supports Perl style as well. Python
In the Perl programming language, autovivification is the automatic creation of new arrays and hashes as required every time an undefined value is dereferenced. Perl autovivification allows a programmer to refer to a structured variable, and arbitrary sub-elements of that structured variable, without expressly declaring the existence of the ...