ColdFusion 真實 List 字串內容

字串清單組合情況會有
1. : a,b,c,,,d
2. : ,a,b,c,,,d
3. : a,b,c,,,d,
4. : ,a,b,c,,,d,

以下這個自定函數都可以解決，會將空的內容以 NULL 字串取代來得到真實的清單長度
1. : a,b,c,,,d ==> a,b,c,NULL,NULL,d
2. : ,a,b,c,,,d ==> NULL,a,b,c,NULL,NULL,d
3. : a,b,c,,,d, ==> a,b,c,NULL,NULL,d,NULL
4. : ,a,b,c,,,d, ==> NULL,a,b,c,NULL,NULL,d,NULL

<br /><cffunction name="listWithNullsTolist" access="remote"<br /> displayname="真實 List 字串內容"<br /> hint="回傳 List 字串"><br /> <cfargument name="sourceList" required="true" displayname="原始 List 字串"><br /> <cfargument name="null_var" default="NULL" displayname="元素空值取代字串"><br /> <cfargument name="delim" default="," displayname="原始 List 字串的分隔符號"><br /><br /> <cfset delim_len = Len(delim)><br /><br /> <cfif Left(sourceList,delim_len) EQ delim><br /> <cfset sourceList = null_var & sourceList><br /> </cfif><br /><br /> <cfif Right(sourceList,delim_len) EQ delim><br /> <cfset sourceList = sourceList & null_var><br /> </cfif><br /><br /> <cfloop condition="Find(delim & delim,sourceList) NEQ 0"><br /> <cfset sourceList = Replace(sourceList,delim & delim,delim & null_var & delim)><br /> </cfloop><br /> <br /> <cfreturn sourceList><br /></cffunction><br /><br /><cfoutput><br />1. : a,b,c,,,d == > #listWithNullsTolist("a,b,c,,,d")#<br><br />2. : ,a,b,c,,,d == > #listWithNullsTolist(",a,b,c,,,d")#<br> <br />3. : a,b,c,,,d, == > #listWithNullsTolist("a,b,c,,,d,")#<br><br />4. : ,a,b,c,,,d, == > #listWithNullsTolist(",a,b,c,,,d,")#<br><br /></cfoutput><br />
執行結果︰
<br />1. : a,b,c,,,d == > a,b,c,NULL,NULL,d<br />2. : ,a,b,c,,,d == > NULL,a,b,c,NULL,NULL,d<br />3. : a,b,c,,,d, == > a,b,c,NULL,NULL,d,NULL<br />4. : ,a,b,c,,,d, == > NULL,a,b,c,NULL,NULL,d,NULL<br />