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In Python, a generator can be thought of as an iterator that contains a frozen stack frame. Whenever next() is called on the iterator, Python resumes the frozen frame, which executes normally until the next yield statement is reached. The generator's frame is then frozen again, and the yielded value is returned to the caller.
Here, the list [0..] represents , x^2>3 represents the predicate, and 2*x represents the output expression.. List comprehensions give results in a defined order (unlike the members of sets); and list comprehensions may generate the members of a list in order, rather than produce the entirety of the list thus allowing, for example, the previous Haskell definition of the members of an infinite list.
In Python 3.x the range() function [28] returns a generator which computes elements of the list on demand. Elements are only generated when they are needed (e.g., when print(r[3]) is evaluated in the following example), so this is an example of lazy or deferred evaluation:
PHP has hundreds of base functions and thousands more from extensions. Prior to PHP version 5.3.0, functions are not first-class functions and can only be referenced by their name, whereas PHP 5.3.0 introduces closures. [35] User-defined functions can be created at any time and without being prototyped. [35]
In JavaScript, PHP, VBScript and a few other dynamically typed languages, the standard equality operator follows so-called loose typing, that is it evaluates to true even if two values are not equal and are of incompatible types, but can be coerced to each other by some set of language-specific rules, making the number 4 compare equal to the ...
The eval() vs. exec() built-in functions (in Python 2, exec is a statement); the former is for expressions, the latter is for statements Statements cannot be a part of an expression—so list and other comprehensions or lambda expressions , all being expressions, cannot contain statements.
This category is not shown on its member pages unless the appropriate user preference (appearance → show hidden categories) is set. Pages in category "Articles with example PHP code" The following 35 pages are in this category, out of 35 total.
The enclosed text becomes a string literal, which Python usually ignores (except when it is the first statement in the body of a module, class or function; see docstring). Elixir The above trick used in Python also works in Elixir, but the compiler will throw a warning if it spots this.