Method len

arrow-array/src/builder/struct_builder.rs:124–126

Returns the number of array slots in the builder. Note that this always return the first child field builder's length, and it is the caller's responsibility to maintain the consistency that all the child field builder should have the equal number of elements.

(&self)

    /// the caller's responsibility to maintain the consistency that all the child field
    /// builder should have the equal number of elements.
    fn len(&self) -> usize {
        self.null_buffer_builder.len()
    }

    /// Builds the array.
    fn finish(&mut self) -> ArrayRef {