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^c In Perl, the "my" keyword scopes the variable into the block. ^d Technically, this does not declare name to be a mutable variable—in ML, all names can only be bound once; rather, it declares name to point to a "reference" data structure, which is a simple mutable cell.
The structure of the Perl programming language encompasses both the syntactical rules of the language and the general ways in which programs are organized. Perl's design philosophy is expressed in the commonly cited motto "there's more than one way to do it".
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
Perl provides three loop control keywords that all accept an optional loop label as an argument. If no label is specified, the keywords act on the innermost loop. Within nested loops, the use of labels enables control to move from an inner loop to an outer one, or out of the outer loop altogether.
The placeholder may be a variable name, or in some languages an arbitrary expression, in either case evaluated in the current context. String interpolation is an alternative to building string via concatenation , which requires repeat quoting and unquoting; [ 2 ] or substituting into a printf format string , where the variable is far from where ...
Such programs are called "scripts". In this regard, perl is considered to be a scripting language. Typical operations performed by shell scripts include program execution, printing text, and file manipulation (copying, renaming, deleting, etc.). Being an interpreted language, perl has the following advantages: Platform independence
In array languages, operations are generalized to apply to both scalars and arrays. Thus, a+b expresses the sum of two scalars if a and b are scalars, or the sum of two arrays if they are arrays. An array language simplifies programming but possibly at a cost known as the abstraction penalty.
Perl Data Language (abbreviated PDL) is a set of free software array programming extensions to the Perl programming language. PDL extends the data structures built into Perl, to include large multidimensional arrays , and adds functionality to manipulate those arrays as vector objects.