@isempty |

Test for empty string.

Syntax: @isempty(arg)

arg: string

Return: number

Tests arg for an empty string.

Return value is an integer (0, 1). An argument which test as missing return a 1, and 0 otherwise.

When used with series objects, the test is performed for every observation in the workfile sample. Note that when used with string matrix objects, the comparison is a test of all of the elements of the matrix, and will return 0 if any element is not empty. Element tests are available in
@eisna.

Equivalent to the more general
@isna when applied to string data.

Examples

Define the string objects

string s1 = "abc"

string s2 = ""

Then

scalar b1 = @isempty("abc")

scalar b2 = @isempty(s1)

sets the scalar objects B1 and B2 to 0, while

scalar c1 = @isempty("")

sets C1 to 1.

If ALPHA1 is an alpha series,

series d1 = @isempty(alpha1)

tests ALPHA1 for an empty string for each observation in the workfile sample.

svector svec1 = @fill("abc", "abc", "")

scalar sc1 = @isempty(svec1)

returns 0, since the command is a full test of SC1 for missing values and returns a 0 if any element is not equal.

Cross-references