Detect Null Values
Functions isNull or hasNull detect null values.
isNull
returns a scalar or a vector depending on the input data;
hasNull
always returns 0 or 1 indicating if an object contains at
least one null value.
isNull(00i);
// output: 1
isNull(-128c);
// output: 1
// the minimum char is reserved for null value
isNull(1 NULL 2);
// output: [0,1,0]
hasNull(1 NULL 2);
// output: 1