Type Conversion

Converting an expression of a given type to another type is known as type-conversion. In nGQL, type conversion is divided into implicit conversion and explicit conversion.

Implicit Type Conversion

Implicit conversions are automatically performed when a value is copied to a compatible type.

  1. Following types can implicitly converted to bool:

    • The conversions from/to bool consider false equivalent to 0 for empty string types, true is equivalent to all other values.
    • The conversions from/to bool consider false equivalent to 0 for int types, true is equivalent to all other values.
    • The conversions from/to bool consider false equivalent to 0.0 for float types, true is equivalent to all other values.

  2. int can implicitly converted to double.

Explicit Type Conversion

In addition to implicit type conversion, explicit type conversion is also supported in case of semantics compliance. The syntax is similar to the C language:

(type_name)expression.

For example, the results of YIELD length((string)(123)), (int)"123" + 1 are 3, 124 respectively. The results of YIELD (int)(TRUE) is 1. And YIELD (int)("12ab3") fails in conversion.