How to check for empty string?

The isEmpty() method checks whether a string is empty or not. This method returns true if the string is empty (length() is 0), and false if not. How to check for empty string in js? Answer: Use the === Operator You can use the strict equality operator ( === ) to check whether a string

Defining variables by selection

What is meant by variable selection? Variable selection means choosing among many variables which to include in a particular model, that is, to select appropriate variables from a complete list of variables by removing those that are irrelevant or redundant.  How do you define a selection variable in SAP? Procedure Call up the transaction STVARV

Rasters to PostGIS

Can you store raster in PostGIS? The raster data type in PostGIS can be used to store any kind of raster data: images, elevation grids, model outputs, and more. One band, four band, multi-band and anything in between. This flexibility leads some beginners to dump all their imagery into the database as “step one” in

How can I access second (or even third) level attributes in a vector layer and add them to the attribute table?

How do I view attribute tables in QGIS? Open Attribute Table button in the Attributes toolbar. This will open a new window that displays the feature attributes for the layer (figure_attributes_table). According to the setting in Settings ‣ Options ‣ Data sources menu, the attribute table will open in a docked window or a regular

How do algorithms load pieces of maps?

How do map routing algorithms work? Google Maps essentially uses two Graph algorithms – Dijkstra’s algorithm and A* algorithm, to calculate the shortest distance from point A ( Source) to point B ( destination). A graph data structure is essentially a collection of nodes that are defined by edges and vertices.  What is mapping algorithms?

SQL query on array data in ArcGIS attribute table

How do I query an attribute table? Selecting records in a table by attributes Click Table Options in the table you want to query and click Select By Attributes . Click the Method arrow and click the selection procedure you want to use. Double-click the field from which you want to select. Click the logical

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