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

Basketball

Basketball is a sport played by two teams of five players on a rectangular court. The objective is to shoot a ball through a hoop 18 inches (46 cm) in diameter and 10 feet (3.048 m) high mounted to a backboard at each end.

A team can score a field goal by shooting the ball through the basket during regular play. A field goal scores three points for the shooting team if the player shoots from behind the three-point line, and two points if shot from in front of the line. A team can also score via free throws, which are worth one point, after the other team was assessed with certain fouls. The team with the most points at the end of the game wins, but additional time (overtime) is issued when the score is tied at the end of regulation. The ball can be advanced on the court by throwing it to a teammate, or by bouncing it while walking or running (dribbling). It is a violation to lift, or drag, one's pivot foot without dribbling the ball, to carry it, or to hold the ball with both hands then resume dribbling.

Im (Korean surname)

Im or Rim is a common Korean family name equivalent either to the Chinese surname Lin or Ren depending on the clan branch.

History

The first clan branch is the Supul Rim (수풀 림, meaning Forest-Rim) and its Hanja character is 林. The Supul Rim branch consists of two large clan houses; the first is Naju (early Hoijin) and the second, which is the elder branch is Pyeongtaek. Members of this branch often write their names as both 임 (Im; more common) and 림 (Rim). The character 林 means "forest".

The second clan branch is the Matgil Im (맡길 임) or Mateul Im (맡을 임) and its Hanja character is 任. The Matgil Im/Mateul Im branch consists of one large clan house called Pungcheon (풍천) and a smaller clan house called Jangheung (장흥). Members of this clan branch both write and pronounce their names as 임 (Im). The character 任 means "trusted/to bear, duty".

Romanization

When 林 (임/림) is romanized, it is usually spelled as "Rim", or occasionally as "Lim". When 任 (임) is romanized, it is usually spelled as "Im", although is sometimes spelled "Yim".

Rim (craters)

The rim or edge of a crater is the part that extends above the height of the local surface, usually in a circular or elliptical pattern. In a more specific sense, the rim may refer to the circular or elliptical edge that represents the uppermost tip of this raised portion. If there is no raised portion, the rim simply refers to the inside edge of the curve where the flat surface meets the curve of the crater bottom.