The phrase "do loop" in computer programming refers to a repetitive structure, commonly found in languages such as BASIC or FORTRAN. The spelling of the word "do loop" is straightforward if one has a basic understanding of English phonetics. The sounds represented by "do" and "loop" can be transcribed with the International Phonetic Alphabet (IPA) as /du/ and /lu:p/, respectively. The pronunciation of the two words put together might sound like "doo-luup." The term refers to a control statement that allows for the repetition of a specific set of instructions until a predetermined condition is met.
A "do loop" is a programming construct that allows a sequence of instructions to be repeated until a certain condition is met. It is a control structure used in many programming languages to implement iteration or looping.
In a "do loop," the instructions within the loop's body are executed repeatedly as long as a specified condition remains true. The loop first executes the instructions, and then checks the condition. If the condition still holds true, the loop iterates again, executing the instructions once more. This process continues until the condition becomes false, at which point the loop terminates, and the program resumes executing the next instructions following the loop.
The key feature of a "do loop" is that the instructions are always executed at least once before the condition is checked. This ensures that the loop is executed even if the condition is initially false, making it useful for situations where a specific number of iterations is required or when the loop must run at least once.
The condition used in a "do loop" can be based on Boolean expressions, such as equality or inequality comparisons, or any other condition that evaluates to either true or false. The loop continues until the condition becomes false, allowing flexibility in creating loops that terminate based on various factors. Additionally, the loop can be controlled by altering variables or using other programming statements within the loop's body, allowing for dynamic and adaptable looping structures.
The term "do loop" is derived from computer programming, particularly from the earlier programming languages such as Fortran. In Fortran, the term refers to a control structure or loop that repeats a block of code until a certain condition is met. It is essentially a combination of the "do" statement, which indicates the start of the loop, and the "loop" statement, which indicates the end of the loop.
The use of the word "do" in programming languages originates from mathematical notation, where it is commonly used to express iterative processes. It is believed that the use of "do" in programming languages was influenced by mathematical notation as a concise way to indicate a loop or repetition.
Over time, as programming languages evolved, different variations of loops were developed, such as "do-while" and "do-until" loops.