Difference between revisions of "LlStringTrim"

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(Noted that llList2Json also trims strings)
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Whenever you are accepting unstructured input from a user -- whether via chat or via a notecard -- it is a good idea to always full trim it:
Whenever you are accepting unstructured input from a user -- whether via chat or via a notecard -- it is a good idea to always full trim it:


<lsl>llStringTrim("User input", STRING_TRIM);</lsl>
<source lang="lsl2">llStringTrim("User input", STRING_TRIM);</source>




This example returns the number of leading and trailing 'white space' characters on a string that were removed (not particularly useful but shows how to use the function).
This example returns the number of leading and trailing 'white space' characters on a string that were removed (not particularly useful but shows how to use the function).
<lsl>
<source lang="lsl2">
default
default
{
{
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     }
     }
}
}
</lsl>
</source>
|helpers
|helpers
|also_functions
|also_functions
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The following will remove all double spaces and leading and trailing spaces.
The following will remove all double spaces and leading and trailing spaces.
<lsl>llDumpList2String(llParseString2List(src, [" "], []), " "); //works but can use a large quantity of memory</lsl>
<source lang="lsl2">llDumpList2String(llParseString2List(src, [" "], []), " "); //works but can use a large quantity of memory</source>


This method strips spaces from the sentence and may use less memory
This method strips spaces from the sentence and may use less memory
<lsl>
<source lang="lsl2">
//Added By To-mos Codewarrior
//Added By To-mos Codewarrior
string str1 = "some words to remove the spaces from";
string str1 = "some words to remove the spaces from";
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     data=llDeleteSubString(str1,index,index);
     data=llDeleteSubString(str1,index,index);
}
}
</lsl>
</source>
The following will do the same:
The following will do the same:
<lsl>(string)llParseString2List(src, [" "], []); //works but can use a large quantity of memory</lsl>
<source lang="lsl2">(string)llParseString2List(src, [" "], []); //works but can use a large quantity of memory</source>
 
[[llList2Json]] also trims strings contained in the list. Thus, an easy way to trim an entire list of strings is:
<source lang="lsl2">
list l = ["  a  ", " b", "c ", " d "];
list trimmedList = llJson2List(llList2Json(JSON_ARRAY, l));
</source>
 


|deprecated
|deprecated
|cat1=String
|cat1=String
|haiku={{Haiku|Less around my ears|And off the collar this time.|Just not too short, please.}}
|cat2
|cat2
|cat3
|cat3
|cat4
|cat4
}}
}}

Revision as of 18:11, 20 April 2017

Summary

Function: string llStringTrim( string src, integer type );

Returns a string that is src with leading and/or trailing white space (spaces, tabs, and line feeds) trimmed from it.

• string src
• integer type – STRING_TRIM* flag(s)

Constant Description
STRING_TRIM_HEAD 0x1 Trims white space off the beginning.
STRING_TRIM_TAIL 0x2 Trims white space off the end.
STRING_TRIM 0x3 Trims white space off the beginning and end.

Examples

Whenever you are accepting unstructured input from a user -- whether via chat or via a notecard -- it is a good idea to always full trim it: 

llStringTrim("User input", STRING_TRIM);


This example returns the number of leading and trailing 'white space' characters on a string that were removed (not particularly useful but shows how to use the function). 

default
{
    state_entry()
    {
        llListen(4, "", llGetOwner(), "");
    }

    on_rez(integer start_param)
    {
        llResetScript();
    }

    listen(integer channel, string name, key id, string message)
    {       
        //track the length
        integer length = llStringLength(message);
        
        //trim message (not necessary to store these to variables but makes reading easier)
        string trim_left  = llStringTrim(message, STRING_TRIM_HEAD);
        string trim_right = llStringTrim(message, STRING_TRIM_TAIL);
        string trim_both  = llStringTrim(message, STRING_TRIM);

        //output the results
        llOwnerSay("Initial length  = " + (string)length +
                 "\nLeading Spaces  = " + (string)(length - llStringLength(trim_left))+
                 "\nTrailing Spaces = " + (string)(length - llStringLength(trim_right))+
                 "\nTrimmed Message = \"" + trim_both + "\"");
    }
}

Notes

Aside from white space at the beginning and / or end, the actual string will be unaffected. This means too, though, that extraneous spaces within the string -- for instance, a mistaken double-space type -- will not be corrected.

The following will remove all double spaces and leading and trailing spaces. 

llDumpList2String(llParseString2List(src, [" "], []), " "); //works but can use a large quantity of memory

This method strips spaces from the sentence and may use less memory 

//Added By To-mos Codewarrior
string str1 = "some words to remove the spaces from";
integer index;
while(~index=llSubStringIndex(str1," ")) {
    data=llDeleteSubString(str1,index,index);
}

The following will do the same: 

(string)llParseString2List(src, [" "], []); //works but can use a large quantity of memory

llList2Json also trims strings contained in the list. Thus, an easy way to trim an entire list of strings is: 

list l = ["  a  ", " b", "c ", " d "];
list trimmedList = llJson2List(llList2Json(JSON_ARRAY, l));

Deep Notes

History

  • Introduced in 1.13.4
Date of release 25-04-2007

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Signature

function string llStringTrim( string src, integer type );
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