Left (String function): Difference between revisions
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===Syntax terms=== | ===Syntax terms=== | ||
<table | <table> | ||
<tr><th>%outString</th> | <tr><th>%outString</th> | ||
<td>A variable to receive the string result of the <var>Left</var> method.</td></tr> | <td>A variable to receive the string result of the <var>Left</var> method.</td></tr> | ||
<tr><th>string</th> | <tr><th>string</th> | ||
<td>The input, method object <var class="term">string</var> to which the method is applied.</td></tr> | <td>The input, method object <var class="term">string</var> to which the method is applied.</td></tr> | ||
<tr><th>length</th> | <tr><th>length</th> | ||
<td>The number of the left-most bytes to return. If the method object is shorter than the requested number of bytes, it is either padded to the requested length or the entire method object string is returned with no padding, depending on the value of the <var>Pad</var> parameter.</td></tr> | <td>The number of the left-most bytes to return. If the method object is shorter than the requested number of bytes, it is either padded to the requested length or the entire method object string is returned with no padding, depending on the value of the <var>Pad</var> parameter.</td></tr> | ||
<tr><th><var>Pad</var></th> | <tr><th><var>Pad</var></th> | ||
<td>This optional, [[Notation conventions for methods#Named parameters|name required]], parameter is the character used to pad the method object string on the right if it is shorter than the requested length. <var class="term">c</var> defaults to a blank. If set to null, no padding is applied. | <td>This optional, [[Notation conventions for methods#Named parameters|name required]], parameter is the character used to pad the method object string on the right if it is shorter than the requested length. <var class="term">c</var> defaults to a blank. If set to null, no padding is applied. | ||
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==Usage notes== | ==Usage notes== | ||
<ul> | <ul> | ||
<li>The <var class="term">length</var> value must be a non-negative number. A negative number results in request cancellation. | <li>The <var class="term">length</var> value must be a non-negative number. A negative number results in request cancellation. </li> | ||
<li>The <var>Pad</var> parameter value must be either null or a single character. A longer value results | |||
<li><var>Left</var> is identical to the <var>[[Substring (String function)|Substring]]</var> method with | <li>The <var>Pad</var> parameter value must be either null or a single character. A longer value results in a compilation error. </li> | ||
< | |||
<li><var>Left</var> is identical to the <var>[[Substring (String function)|Substring]]</var> method with <code>1</code> as its first argument. </li> | |||
</ul> | </ul> | ||
==Examples== | ==Examples== | ||
<ol><li>The following statement places the left-most 5 bytes of <code>%x</code> into <code>%y</code>. If <code>%x</code> contains fewer than 6 bytes, then all of <code>%x</code> is copied into <code>%y</code>, padded on the right with blanks: | <ol> | ||
<li>The following statement places the left-most 5 bytes of <code>%x</code> into <code>%y</code>. If <code>%x</code> contains fewer than 6 bytes, then all of <code>%x</code> is copied into <code>%y</code>, padded on the right with blanks: | |||
<p class="code">%y = %x:left(5) | <p class="code">%y = %x:left(5) | ||
</p> | </p> | ||
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==See also== | ==See also== | ||
<ul> | |||
<li><var>[[UnicodeLeft (Unicode function)|UnicodeLeft]]</var> </li> | |||
<li><var>[[Right (String function)|Right]]</var> and <var>[[UnicodeRight (Unicode function)|UnicodeRight]]</var> </li> | |||
<li><var>[[Center (String function)|Center]]</var> </li> | |||
</ul> | |||
{{Template:String:Left footer}} | {{Template:String:Left footer}} | ||
Latest revision as of 18:08, 11 July 2017
The left-most characters of the string (String class)
The Left intrinsic function returns the left-most characters of the method object string, possibly padding it on the right.
Syntax
%outString = string:Left( length, [Pad= c])
Syntax terms
| %outString | A variable to receive the string result of the Left method. |
|---|---|
| string | The input, method object string to which the method is applied. |
| length | The number of the left-most bytes to return. If the method object is shorter than the requested number of bytes, it is either padded to the requested length or the entire method object string is returned with no padding, depending on the value of the Pad parameter. |
| Pad | This optional, name required, parameter is the character used to pad the method object string on the right if it is shorter than the requested length. c defaults to a blank. If set to null, no padding is applied. |
Usage notes
- The length value must be a non-negative number. A negative number results in request cancellation.
- The Pad parameter value must be either null or a single character. A longer value results in a compilation error.
- Left is identical to the Substring method with
1as its first argument.
Examples
- The following statement places the left-most 5 bytes of
%xinto%y. If%xcontains fewer than 6 bytes, then all of%xis copied into%y, padded on the right with blanks:%y = %x:left(5)
- The following statement displays
Wheeeee:printText {'Wh':left(7, pad='e')}