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| | A lagging computer is actually annoying and is very a headache. Almost every individual who uses a computer faces this problem certain time or the different. If your computer additionally suffers within the same problem, there are it hard to continue working because usual. In such a condition, the thought, "what must I do to create my PC run quicker?" is repeated plus infuriating. There's a answer, though!<br><br>So one day my computer suddenly started being weird. I was thus frustrated, because my files were missing, plus I cannot open the files that I needed, and then, suddenly, everything stopped working!<br><br>The Windows registry is a program database of info. Windows plus alternative software store a great deal of settings and alternative info inside it, plus retrieve such info within the registry all time. The registry is moreover a bottleneck in which considering it's the heart of the operating system, any difficulties with it could result mistakes plus bring the running system down.<br><br>There are tips to make a slow computer function efficient plus fast. In this article, I might tell you only 3 many effective tips or ways to avoid a computer of being slow and instead of that create it faster plus function even much better than before.<br><br>If you are searching for the number one [http://bestregistrycleanerfix.com/tune-up-utilities tuneup utilities] program, make sure to look for one which defragments the registry. It should also scan for assorted things, such as invalid paths and invalid shortcuts and programs. It must equally identify invalid fonts, check for device driver issues plus repair files. Also, be sure which it has a scheduler. That way, we can set it to scan a system at certain times on certain days. It sounds like a lot, however, it really is absolutely vital.<br><br>Another key element when you compare registry products is having a facility to manage a start-up tasks. This just means that you can select what programs we would like to commence whenever you commence your PC. If you have unwanted programs starting whenever we boot up the PC this will cause a slow running computer.<br><br>By restoring the state of your program to an earlier date, error 1721 might not appear in Windows 7, Vista plus XP. There is a tool called System Restore that we have to use in this procedure.<br><br>Thus, the greatest thing to do whenever your computer runs slow is to buy an authentic plus legal registry repair tool that would aid you eliminate all issues connected to registry and aid you enjoy a smooth running computer. |
| In [[formal language theory]], the '''empty string''' (or '''null string''')<ref name="Kernighan and Ritchie, C, p. 38">Kernighan and Ritchie, ''C'', p. 38</ref> is the unique [[string (computer science)|string]] of [[String (computer science)#Formal theory|length]] [[zero]].
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| ==Formal theory==
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| Formally, a string is a finite sequence of symbols such as letters or digits.
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| The empty string is the extreme case where the sequence has length zero, so there are no symbols in the string.
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| There is only one empty string, because two strings are only different if they have different lengths or a different sequence of symbols. | |
| In formal treatments,<ref>JOHN CORCORAN, WILLIAM FRANK, and MICHAEL MALONEY, String theory, Journal of Symbolic Logic, vol. 39 (1974) pp. 625– 637</ref> the empty string is denoted with ''[[ε]]'' or sometimes Λ or [[λ]].
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| The empty string should not be confused with the '''empty language''' ∅, which is a [[formal language]] (i.e. a set of strings) that contains no strings, not even the empty string. | |
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| The empty string has several properties: | |
| *<math>| \epsilon \, | = 0</math>. The '''[[String (computer science)#Formal theory|string length]]''' is zero.
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| *<math>\epsilon \, + s = s + \epsilon \, = s</math>. The empty string is the [[identity element]] of the '''[[union]]''' operation (which forms a [[free monoid]] on the [[alphabet]] Σ).
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| *<math>{ \epsilon \, }^R = \epsilon \,</math>. '''Reversal''' of the empty string produces the empty string.
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| * The empty string precedes any other string under [[lexicographical order]], because it is the shortest of all strings.<ref>[http://cs.fit.edu/~ryan/cse1002/lectures/lexicographic.pdf CSE1002 Lecture Notes - Lexicographic]</ref>
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| ==Use in programming languages==
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| In most programming languages, strings are a [[data type]]. Individual strings are typically stored in consecutive [[Memory address|memory locations]].
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| This means that the same string (for example the empty string) could be stored in two different places in memory.
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| (Note that even a string of length zero can require memory to store it, depending on the format being used.)
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| In this way there could be multiple empty strings in memory, in contrast with the formal theory definition, for which there is only one possible empty string.
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| However, a string comparison function would indicate that all of these empty strings are equal to each other.
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| The empty string is distinct from a [[null pointer|null]] [[Reference (computer science)|reference]] (or null pointer) because a null reference does not point to any string at all, not even the empty string.
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| A null reference is likely to cause an error if one tries to perform any operation on it, but an empty string is less likely to do so.
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| The empty string is a legitimate string, upon which most string operations should work. Some languages treat some or all of the following in similar ways, which can lessen the danger: empty strings, null references, the integer 0, the floating point number 0, the boolean value [[False (logic)|false]], the [[ascii]] character [[null character|NUL]], or other such values.
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| The empty string is usually represented similarly to other strings. In implementations with string terminating character ([[null-terminated string]]s or plain text lines), the empty string is indicated by the immediate use of this terminating character.
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| {| class="wikitable"
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| |-
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| ! λ representation
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| ! Programming languages
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| |-
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| | <code>""</code>
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| | [[C (programming language)|C]], [[C++]], [[Perl]], [[Python (programming language)|Python]], [[C Sharp (programming language)|C#]], [[Go (programming language)|Go]], [[PHP]], [[Visual Basic .NET]], [[Java (programming language)|Java]], [[Turing (programming language)|Turing]], [[JavaScript]], [[Haskell (programming language)|Haskell]], [[Objective-C]] (as a C string), [[OCaml]], [[Standard ML]], [[Scala (programming language)|Scala]], [[Seed7]], [[Tcl (programming language)|Tcl]]
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| |-
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| | <code>''</code>
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| | [[Perl]], [[PHP]], [[Python (programming language)|Python]], [[JavaScript]], [[Delphi (programming language)|Delphi]], [[Pascal (programming language)|Pascal]], [[Matlab (programming language)|Matlab]]
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| |-
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| | <code>{'\0'}</code>
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| | [[C (programming language)|C]], [[C++]], [[Objective-C]] (as a C string)
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| |-
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| | <code>std::string()</code>
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| | [[C++]]
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| |-
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| | <code>@""</code>
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| | [[Objective-C]] (as a constant <code>NSString</code> object)
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| |-
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| | <code>[NSString string]</code>
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| | [[Objective-C]] (as a new <code>NSString</code> object)
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| |-
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| | <code>q(), qq()</code>
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| | [[Perl]]
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| |-
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| | <code>%{}</code>
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| | [[Ruby]]
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| |-
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| | <code>""""""</code><br/><code>str()</code>
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| | [[Python (programming language)|Python]]
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| |-
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| | <code>string.Empty</code>
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| | [[C Sharp (programming language)|C#]], [[VB.NET|Visual Basic .NET]]
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| |-
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| | <code>String.make 0 '-'</code>
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| | [[OCaml]]
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| |-
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| | <code>{}</code>
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| | [[Tcl]]
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| |-
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| |}
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| === Examples of empty strings ===
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| {{Expand section|date=March 2010}}
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| The empty string is a syntactically valid representation of [[0 (number)|zero]] in [[positional notation]] (in any base), which does not contain [[leading zero]]s. Since the empty string does not have a standard visual representation outside of formal language theory, the number zero is traditionally represented by a single [[decimal digit]] '''0''' instead.
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| Zero-filled memory area, interpreted as a [[null-terminated string]], is an empty string.
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| Empty lines of text show the empty string. This can occur from two consecutive [[End of line|EOLs]], as often occur in [[text file]]s, and this is sometimes used in [[text processing]] to separate [[paragraph]]s, e.g. in [[MediaWiki]].
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| ==See also==
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| *[[Empty set]]
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| *[[Null-terminated string]]
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| *[[Concatenation theory]]
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| *[[Concatenation]]
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| ==References==
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| {{Reflist}}
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| {{nulls}}
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| {{DEFAULTSORT:Empty String}}
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| [[Category:Formal languages]]
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| [[Category:String (computer science)]]
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| [[Category:Zero]]
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A lagging computer is actually annoying and is very a headache. Almost every individual who uses a computer faces this problem certain time or the different. If your computer additionally suffers within the same problem, there are it hard to continue working because usual. In such a condition, the thought, "what must I do to create my PC run quicker?" is repeated plus infuriating. There's a answer, though!
So one day my computer suddenly started being weird. I was thus frustrated, because my files were missing, plus I cannot open the files that I needed, and then, suddenly, everything stopped working!
The Windows registry is a program database of info. Windows plus alternative software store a great deal of settings and alternative info inside it, plus retrieve such info within the registry all time. The registry is moreover a bottleneck in which considering it's the heart of the operating system, any difficulties with it could result mistakes plus bring the running system down.
There are tips to make a slow computer function efficient plus fast. In this article, I might tell you only 3 many effective tips or ways to avoid a computer of being slow and instead of that create it faster plus function even much better than before.
If you are searching for the number one tuneup utilities program, make sure to look for one which defragments the registry. It should also scan for assorted things, such as invalid paths and invalid shortcuts and programs. It must equally identify invalid fonts, check for device driver issues plus repair files. Also, be sure which it has a scheduler. That way, we can set it to scan a system at certain times on certain days. It sounds like a lot, however, it really is absolutely vital.
Another key element when you compare registry products is having a facility to manage a start-up tasks. This just means that you can select what programs we would like to commence whenever you commence your PC. If you have unwanted programs starting whenever we boot up the PC this will cause a slow running computer.
By restoring the state of your program to an earlier date, error 1721 might not appear in Windows 7, Vista plus XP. There is a tool called System Restore that we have to use in this procedure.
Thus, the greatest thing to do whenever your computer runs slow is to buy an authentic plus legal registry repair tool that would aid you eliminate all issues connected to registry and aid you enjoy a smooth running computer.