Reports the length of a string or a blob.
Len ( stringorblob )
Argument |
Description |
---|---|
stringorblob |
The string or blob for which you want the length in number of characters or in number of bytes |
Long. Returns a long whose value is the length of stringorblob if it succeeds and -1 if an error occurs. If stringorblob is null, Len returns null.
Len counts the number of characters in a string. The null that terminates a string is not included in the count.
If you specify a size when you declare a blob, that is the size reported by Len. If you do not specify a size for the blob, Len initially reports the blob’s length as 0. PowerBuilder assigns a size to the blob the first time you assign data to the blob. Len reports the length of the blob as the number characters it can contain.
This statement returns 0:
Len("")
These statements store in the variable s_address_len the length of the text in the SingleLineEdit sle_address:
long s_address_len
s_address_len = Len(sle_address.Text)
The following scenarios illustrate how the declaration of blobs affects their length, as reported by Len.
In the first example, an instance variable called ib_blob is declared but not initialized with a size. If you call Len before data is assigned to ib_blob, Len returns 0. After data is assigned, Len returns the blob’s new length.
The declaration of the instance variable is:
blob ib_blob
The sample code is:
long ll_len
ll_len = Len(ib_blob) // ll_len set to 0
ib_blob = Blob( "Test String")
ll_len = Len(ib_blob) // ll_len set to 22
In the second example, ib_blob is initialized to the size 100 when it is declared. When you call Len for ib_blob, it always returns 100. This example uses BlobEdit, instead of Blob, to assign data to the blob because its size is already established. The declaration of the instance variable is:
blob{100} ib_blob
The sample code is:
long ll_len
ll_len = Len(ib_blob) // ll_len set to 100
BlobEdit(ib_blob, 1, "Test String")
ll_len = Len(ib_blob) // ll_len set to 100
Len method for DataWindows in the DataWindow Reference or the online Help