A nested loop is a logical structure used in computer programming and coding. It is characterized by two or more repeating statements that are placed in a "nested" form, which is to say that one “loop” or repeating command is situated within the body of the other. It is an efficient and in most cases relatively simple way for coders and programmers to cause sequential events and actions that build upon each other through an interrelated series of commands and signal switchbacks. Nested loops are a common part of most computer programs but can also be found in many situations where technology intersects with the presentation of some sort of information.
Why It’s Used
Looping is a powerful construct in programming as it allows rapid sorting or insertion of large amounts of data in an efficient way. Solving problems in the business world, for instance, or in manufacturing, often involves repeating an action over and over with hundreds, thousands, or even millions of individual pieces of data. As a resuly, loops are frequently used constructs in all kinds of computer programs in all types of industries.
Relationship Between Loops
The outer loop and any and all inner loops are related to each other in important ways. Not only are they connected, but they also take signals from each other and depend on each other for the translation and completion of various signals and digital tasks. The specifics tend to vary depending on application, but near constant communication is almost always a given.
In most cases the outer loop is what causes the inner loop to execute. The inner loop then repeats for as many times as is specified in the code or command materials. When the inner loop completes, the outer loop is executed for its second iteration, triggering the inner loop again, and so on until the requirements for the outer loop are complete.
Many computer programmers work in Structured Query Language (SQL), and nesting is of particular relevance in these cases. It essentially provides a means through which a person can quickly and efficiently search data in two linked tables. An outer loop is used to read the first table, one row of data at a time; then the data required to search the second table is passed to the inner loop, which reads the second table. As a result, the loop can process two linked tables in an efficient manner. Most of the time this all happens almost instantaneously.