What is the difference between the &
and &&
logical operators in MATLAB?
This question is related to
matlab
logical-operators
short-circuiting
&
is a logical elementwise operator, while &&
is a logical short-circuiting operator (which can only operate on scalars).
For example (pardon my syntax).
If..
A = [True True False True]
B = False
A & B = [False False False False]
..or..
B = True
A & B = [True True False True]
For &&
, the right operand is only calculated if the left operand is true, and the result is a single boolean value.
x = (b ~= 0) && (a/b > 18.5)
Hope that's clear.
&& and || are short circuit operators operating on scalars. & and | operate on arrays, and use short-circuiting only in the context of if
or while
loop expressions.
A good rule of thumb when constructing arguments for use in conditional statements (IF, WHILE, etc.) is to always use the &&/|| forms, unless there's a very good reason not to. There are two reasons...
Doing this, rather than relying on MATLAB's resolution of vectors in & and |, leads to code that's a little bit more verbose, but a LOT safer and easier to maintain.
Both are logical AND operations. The && though, is a "short-circuit" operator. From the MATLAB docs:
They are short-circuit operators in that they evaluate their second operand only when the result is not fully determined by the first operand.
See more here.
&&
and ||
take scalar inputs and short-circuit always. |
and &
take array inputs and short-circuit only in if/while statements. For assignment, the latter do not short-circuit.
See these doc pages for more information.
As already mentioned by others, &
is a logical AND operator and &&
is a short-circuit AND operator. They differ in how the operands are evaluated as well as whether or not they operate on arrays or scalars:
&
(AND operator) and |
(OR operator) can operate on arrays in an element-wise fashion.&&
and ||
are short-circuit versions for which the second operand is evaluated only when the result is not fully determined by the first operand. These can only operate on scalars, not arrays.Source: Stackoverflow.com