Trimming (computer programming)

In computer programming, trimming (trim) or stripping (strip) is a string manipulation in which leading and trailing whitespace is removed from a string.

For example, the string (enclosed by apostrophes)

would be changed, after trimming, to

Variants

Definition of whitespace

The characters which are considered whitespace varies between programming languages and implementations. For example, C traditionally only counts space, tab, line feed, and carriage return characters, while languages which support Unicode typically include all Unicode space characters. Some implementations also include ASCII control codes (non-printing characters) along with whitespace characters.

Java's trim method considers ASCII spaces and control codes as whitespace, contrasting with the Java isWhitespace() method, which recognizes all Unicode space characters.

Delphi's Trim function considers characters U+0000 (NULL) through U+0020 (SPACE) to be whitespace.

Usage

Following are examples of trimming a string using several programming languages. All of the implementations shown return a new string and do not alter the original variable.

Trim (computing)

A Trim command (known as TRIM in the ATA command set, and UNMAP in the SCSI command set) allows an operating system to inform a solid-state drive (SSD) which blocks of data are no longer considered in use and can be wiped internally.

Trim was introduced soon after SSDs were introduced. Because low-level operation of SSDs differs significantly from hard drives, the typical way in which operating systems handle operations like deletes and formats resulted in unanticipated progressive performance degradation of write operations on SSDs. Trimming enables the SSD to handle garbage collection overhead, which would otherwise significantly slow down future write operations to the involved blocks, in advance.

Although tools to "reset" some drives to a fresh state were already available before the introduction of trimming, they also delete all data on the drive, which makes them impractical to use for ongoing optimization. By 2014 many SSDs had internal idle/background garbage collection mechanisms that work independently of trimming; although this successfully maintains their performance even under operating systems that do not support Trim, it has the associated drawbacks of increased write amplification and wear of the flash cells.

Draft (hull)

The draft (American) or draught (British) of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel), with the thickness of the hull included; in the case of not being included the draft outline would be obtained. Draft determines the minimum depth of water a ship or boat can safely navigate. The draft can also be used to determine the weight of the cargo on board by calculating the total displacement of water and then using Archimedes' principle. A table made by the shipyard shows the water displacement for each draft. The density of the water (salt or fresh) and the content of the ship's bunkers has to be taken into account. The closely related term "trim" is defined as the difference between the forward and aft drafts.

Drafts of a ship

Preview

Preview(s) or The Preview may refer to:

Theatre, film, television

Preview (comics)

Preview (Jessica Vale) is a fictional character, a mutant appearing in comic books published by Marvel Comics. Before being depowered, she had the ability of short-term precognition, usually minutes in advance. She is the sister of fellow Xavier Institute for Higher Learning student Sarah Vale (codename Network). Preview first appeared in New X-Men: Academy X #12 (2005).

Fictional character biography

Paragons squad

Preview is a member of the Paragons training squad at the Xavier Institute, where she is voted the "biggest drama queen". Preview proves to be difficult to the Paragons because she chooses not to participate in some activities because she knows their outcomes, such as the Paragons' failure in a school-wide competition. She shows displeasure at the lack of surprise in everyday life due to the nature of her powers.

Depowered

Preview is one of scores of mutants who lose their powers after the events of the House of M.

It is suggested in New X-Men, vol. 2 #32 that Preview is alive following William Stryker's attack on a bus of depowered students. In this issue, a memorial is held at the school for the departed, and while Jessie's sister Sarah is mentioned as one of the deceased, Jessie is not, and an unnamed girl with a similar appearance to Jessie is seen at the service. In addition, writers Chris Yost and Craig Kyle confirmed that she was not one of the students on the bus at the time of the explosion.

Boost

Boost or boosting may refer to:

Science, technology and mathematics

Food and drinks

Other uses

Confidence

Confidence is generally described as a state of being certain either that a hypothesis or prediction is correct or that a chosen course of action is the best or most effective. Self-confidence is having confidence in oneself. Arrogance or hubris in this comparison is having unmerited confidence—believing something or someone is capable or correct when they are not. Overconfidence or presumptuousness is excessive belief in someone (or something) succeeding, without any regard for failure. Confidence can be a self-fulfilling prophecy as those without it may fail or not try because they lack it and those with it may succeed because they have it rather than because of an innate ability. Taken to an extreme, over-confidence can cause problems as evidenced by the famous author Matthew Syed and mentioned here in this reference in regard to sport.

Self-confidence

Self-confidence does not necessarily imply "self-belief" or a belief in one's ability to succeed. For instance, one may be inept at a particular sport or activity, but remain "confident" in one's demeanor, simply because one does not place a great deal of emphasis on the outcome of the activity. When one does not dwell on negative consequences one can be more "self-confident" because one is worrying far less about failure or the disapproval of others following potential failure. One is then more likely to focus on the actual situation which means that enjoyment and success in that situation is also more probable. Belief in one's abilities to perform an activity comes through successful experience and may add to, or consolidate, a general sense of self-confidence. Studies have also found a link between high levels of confidence and wages. Seemingly, those who self-report they were confident earlier in schooling earned better wages and were promoted more quickly over the life course.