Placeholder directives are used to access variables within template files. They can also be used to perform simple operations and arthmetic calculations. They are denoted by double opening braces and double closing braces {{ }}. The calculations performed within this placeholder only supports a returned data type that can be within the range of integers, floats, strings or booleans. The Returned data type cannot be arrays, functions or objects. This is because the returned data type is printed directly on the web page. The examples below show how the braces can be applied.