Types ===== The default type for variables in Yul is ``u256``. If there is no type specified, the compiler will default to that integer type. Variables can have a type specified during their declaration using the following syntax: .. code-block:: yul { let a : u32, b : s64, d : u128, e : bool := multipleReturns() } Yul allows signed and unsigned integer types, in addition to the boolean type. If a conversion from an integer to a boolean is necessary, the compiler does the following operation ``number != 0``. The unsigned types are the following: ``u8``, ``u32``, ``u64``, ``u128`` and ``u256``. The signed types are the following: ``s8``, ``s32``, ``s64``, ``s128``, ``s256``.