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In computer programs, an important form of control flow is the loop which causes a block of code to be executed more than once. A common idiom is to have a loop nested inside another loop, with the contained loop being commonly referred to as the inner loop.
In many languages there are two main types of loop exist, and they can be nested within each other in multiple layers of nesting. The two types are for loop and while loop. [1] They are slightly different in form but have the same effect. Research has shown that performance of the complete structure of a loop with an inner loop is different when compared with a loop without an inner loop. [2] Indeed, even the performance of two loops with different types of inner loop, where one is a for loop and the other a while loop, are different.
It was observed that more computations are performed per unit time when an inner for loop is involved than otherwise. This implies, given the same number of computations to perform, the one with an inner for loop will finish faster than the one without it. This is a machine- or platform-independent technique of loop optimization and was observed across several programming languages and compilers or interpreters tested. The case of a while loop as the inner loop performed badly, performing even slower than a loop without any inner loop in some cases. Two examples below written in python present a while loop with an inner for loop and a while loop without any inner loop. Although both have the same terminating condition for their while loops, the first example will finish faster because of the inner for loop. The variable innermax is a fraction of the maxticketno variable in the first example. [3]
whileticket_no*innermax<max_ticket_no:forjinrange(0,innermax):if(ticket_no*innermax+j)==jackpot_no:returnticket_no+=1whileticket_no<max_ticket_no:ifticket_no==jackpot_no:returnticket_no+=1In object-oriented programming, a class defines the shared aspects of objects created from the class. The capabilities of a class differ between programming languages, but generally the shared aspects consist of state (variables) and behavior (methods) that are each either associated with a particular object or with all objects of that class.
In computer science, functional programming is a programming paradigm where programs are constructed by applying and composing functions. It is a declarative programming paradigm in which function definitions are trees of expressions that map values to other values, rather than a sequence of imperative statements which update the running state of the program.
In programming language theory, lazy evaluation, or call-by-need, is an evaluation strategy which delays the evaluation of an expression until its value is needed and which also avoids repeated evaluations.
In computer science, syntactic sugar is syntax within a programming language that is designed to make things easier to read or to express. It makes the language "sweeter" for human use: things can be expressed more clearly, more concisely, or in an alternative style that some may prefer. Syntactic sugar is usually a shorthand for a common operation that could also be expressed in an alternate, more verbose, form: The programmer has a choice of whether to use the shorter form or the longer form, but will usually use the shorter form since it is shorter and easier to type and read.
An optimizing compiler is a compiler designed to generate code that is optimized in aspects such as minimizing program execution time, memory use, storage size, and power consumption. Optimization is generally implemented as a sequence of optimizing transformations, algorithms that transform code to produce semantically equivalent code optimized for some aspect. It is typically CPU and memory-intensive. In practice, factors such as available memory and a programmer's willingness to wait for compilation limit the optimizations a compiler might provide. Research indicates that some optimization problems are NP-complete, or even undecidable.
In computer science, control flow is the order in which individual statements, instructions or function calls of an imperative program are executed or evaluated. The emphasis on explicit control flow distinguishes an imperative programming language from a declarative programming language.
In computer programming, the scope of a name binding is the part of a program where the name binding is valid; that is, where the name can be used to refer to the entity. In other parts of the program, the name may refer to a different entity, or to nothing at all. Scope helps prevent name collisions by allowing the same name to refer to different objects – as long as the names have separate scopes. The scope of a name binding is also known as the visibility of an entity, particularly in older or more technical literature—this is in relation to the referenced entity, not the referencing name.
In programming languages, a closure, also lexical closure or function closure, is a technique for implementing lexically scoped name binding in a language with first-class functions. Operationally, a closure is a record storing a function together with an environment. The environment is a mapping associating each free variable of the function with the value or reference to which the name was bound when the closure was created. Unlike a plain function, a closure allows the function to access those captured variables through the closure's copies of their values or references, even when the function is invoked outside their scope.
In computer science, program optimization, code optimization, or software optimization is the process of modifying a software system to make some aspect of it work more efficiently or use fewer resources. In general, a computer program may be optimized so that it executes more rapidly, or to make it capable of operating with less memory storage or other resources, or draw less power.
In object-oriented programming, object copying is the act of creating and initializing a new object based on an existing object's state. The various ways to implement copy have implications that a programmer needs to understand in order to write a computer program that is correct and performant.
In computer programming, an assignment statement sets and/or re-sets the value stored in the storage location(s) denoted by a variable name; in other words, it copies a value into the variable. In most imperative programming languages, the assignment statement is a fundamental construct.
In computer science, conditionals are programming language constructs that perform different computations or actions or return different values depending on the value of a Boolean expression, called a condition.
In computer science, a for-loop or for loop is a control flow statement for specifying iteration. Specifically, a for-loop functions by running a section of code repeatedly until a certain condition has been satisfied.
In computer programming, a nested function is a named function that is defined within another, enclosing, block and is lexically scoped within the enclosing block – meaning it is only callable by name within the body of the enclosing block and can use identifiers declared in outer blocks, including outer functions. The enclosing block is typically, but not always, another function.
E is an object-oriented programming language for secure distributed computing, created by Mark S. Miller, Dan Bornstein, Douglas Crockford, Chip Morningstar and others at Electric Communities in 1997. E is mainly descended from the concurrent language Joule and from Original-E, a set of extensions to Java for secure distributed programming. E combines message-based computation with Java-like syntax. A concurrency model based on event loops and promises ensures that deadlock can never occur.
In compiler theory, loop optimization is the process of increasing execution speed and reducing the overheads associated with loops. It plays an important role in improving cache performance and making effective use of parallel processing capabilities. Most execution time of a scientific program is spent on loops; as such, many compiler optimization techniques have been developed to make them faster.
In computer science, the syntax of a computer language is the rules that define the combinations of symbols that are considered to be correctly structured statements or expressions in that language. This applies both to programming languages, where the document represents source code, and to markup languages, where the document represents data.
In computer science, recursion is a method of solving a computational problem where the solution depends on solutions to smaller instances of the same problem. Recursion solves such recursive problems by using functions that call themselves from within their own code. The approach can be applied to many types of problems, and recursion is one of the central ideas of computer science.
The power of recursion evidently lies in the possibility of defining an infinite set of objects by a finite statement. In the same manner, an infinite number of computations can be described by a finite recursive program, even if this program contains no explicit repetitions.
Cython is a superset of the programming language Python, which allows developers to write Python code that yields performance comparable to that of C.
Goto is a statement found in many computer programming languages. It performs a one-way transfer of control to another line of code; in contrast a function call normally returns control. The jumped-to locations are usually identified using labels, though some languages use line numbers. At the machine code level, a goto is a form of branch or jump statement, in some cases combined with a stack adjustment. Many languages support the goto statement, and many do not.
4. Python Nested For Loop From Techgeekbuz
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