computer science

Spinner (computing)

Spinner (computing) is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Spinner (computing) rather than just read about it. In short: A spinner or numeric updown is a graphical control element with which a user may adjust a value in an adjoining text box by either clicking on an up or down arrow, by pressing an arrow key down or moving mouse wheel, causing the value in the text box to increase (if the up arrow is held down) or decrease (if the down arrow is held down). A spinner is typically oriented vertically.

Key takeaways

Spinner (computing) belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Spinner (computing) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Spinner (computing) from memory before moving on to harder problems.

Reference excerpt

A spinner or numeric updown is a graphical control element with which a user may adjust a value in an adjoining text box by either clicking on an up or down arrow, by pressing an arrow key down or moving mouse wheel, causing the value in the text box to increase (if the up arrow is held down) or decrease (if the down arrow is held down). A spinner is typically oriented vertically. In most cases holding a button down causes the speed at which the associated value changes to increase. Usually, the value of the spinner is displayed in a text box next to the spinner, allowing the user to use the spinner to adjust the value, or to type the value into the text box. The combination of spinner and text box was coined as a Value Box. A spinner is different from a scrollbar or slider in that a spinner is typically used to adjust a value without changing the format of the display or the other information on the screen. Thus, the appearance of the spinner at a given time does not represent the quantity of the associated value.

References

External links Javascript spinner control (up/down buttons): example for emulating spinners for HTML in JavaScript

Illustrations

Worked examples

Example 1 — a first encounter with Spinner (computing)

Start with the simplest possible case. Write down what Spinner (computing) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Spinner (computing) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Spinner (computing) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Spinner (computing)

In research: Spinner (computing) appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Spinner (computing) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Spinner (computing) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Desktop environment stubs, Graphical control elements, Technology neologisms, so understanding it makes those chapters shorter.
In everyday life: Look for Spinner (computing) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Spinner (computing) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Spinner (computing) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Spinner (computing) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Spinner (computing) in simple terms?

Why does Spinner (computing) matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Spinner (computing)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Spinner (computing).