WhichListItem

WhichListItem (itemStr, listStr [, listSepStr [, startIndex [, matchCase]]])

The WhichListItem function returns the index of the first item of listStr that matches itemStr. listStr should contain items separated by listSepStr which typically is ";". If the item is not found in the list, -1 is returned.

Use WhichListItem to locate an item in a string containing a list of items separated by a string (usually a single ASCII character), such as those returned by functions like TraceNameList or AnnotationList, or a line from a delimited text file.

listSepStr, startIndex, and matchCase are optional; their defaults are ";", 0, and 1 respectively.

Details

WhichListItem differs from FindListItem in that WhichListItem returns a list index, while FindListItem returns a character offset into a string.

listStr is searched for itemStr bound by listSepStr on the left and right.

listStr is treated as if it ends with a listSepStr even if it doesn't.

Searches for listSepStr are always case-sensitive. The comparison of itemStr to the contents of listStr is usually case-sensitive. Setting the optional matchCase parameter to 0 makes the comparison case insensitive.

If itemStr is not found, if listStr is "", or if startIndex is not within the range of 0 to ItemsInList(listStr )-1, then -1 is returned.

In Igor 6, only the first byte of listSepStr was used. In Igor 7 and later, all bytes are used.

An item can be empty. The lists "abc;def;;ghi" and ";abc;def;;ghi;" have four items (the third item is ""). Use WhichListItem("", listStr ) to find the first empty item.

If startIndex is specified, then listSepStr must also be specified. If matchCase is specified, startIndex and listSepStr must be specified.

Examples

Print WhichListItem("wave0", "wave0;wave1;")    // prints 0
Print WhichListItem("c", "a;b;")                // prints -1
Print WhichListItem("", "a;;b;")                // prints 1
Print WhichListItem("c", "a,b,c,x,c", ",")      // prints 2
Print WhichListItem("c", "a,b,c,x,c", ",", 3)   // prints 4
Print WhichListItem("C", "x;c;C;")              // prints 2
Print WhichListItem("C", "x;c;C;", ";", 0, 0)   // prints 1

See Also

StringFromList, FindListItem, ItemsInList, AddListItem, RemoveListItem, RemoveFromList, WaveList, TraceNameList, StringList, VariableList, FunctionList