The difference between += and =+
a += b is short-hand for a = a + b (though note that the expression a will only be evaluated once.) a =+ b is a = (+b), i.e. assigning the unary + of b to a. Examples:
operators
What does the question mark character (‘?’) mean in C++?
This is commonly referred to as the conditional operator, and when used like this: … if the condition evaluates to true, the expression evaluates to result_if_true, otherwise it evaluates to result_if_false. It is syntactic sugar, and in this case, it can be replaced with
what is the meaning of == sign?
The == operator tests for equality. For example: And, in your example: x is true (1) if y is equal to z. If y is not equal to z, x is false (0). A common mistake made by novice C programmers (and a typo made by some very experienced ones as well) is: In this case, b is assigned … Read more
What does the power operator (**) in python translate into?
If you’re interested in the internals, I’d disassemble the instruction to get the CPython bytecode it maps to. Using Python3: OK, so that seems to have done the calculation right on entry, and stored the result. You get exactly the same CPython bytecode for 2*2*2 (feel free to try it). So, for the expressions that … Read more
proper name for python * operator?
In Ruby and Perl 6 this has been called “splat”, and I think most people from those communities will figure out what you mean if you call it that. The Python tutorial uses the phrase “unpacking argument lists”, which is long and descriptive. It is also referred to as iterable unpacking, or in the case of **, dictionary unpacking.
proper name for python * operator?
In Ruby and Perl 6 this has been called “splat”, and I think most people from those communities will figure out what you mean if you call it that. The Python tutorial uses the phrase “unpacking argument lists”, which is long and descriptive. It is also referred to as iterable unpacking, or in the case of **, dictionary unpacking.
What does the question mark character (‘?’) mean in C++?
This is commonly referred to as the conditional operator, and when used like this: … if the condition evaluates to true, the expression evaluates to result_if_true, otherwise it evaluates to result_if_false. It is syntactic sugar, and in this case, it can be replaced with Note: Some people refer to ?: it as “the ternary operator“, because it is the only ternary operator (i.e. operator that … Read more
Regex how to match an optional character
Use to make the letter optional. {1} is redundant. (Of course you could also write [A-Z]{0,1} which would mean the same, but that’s what the ? is there for.) You could improve your regex to And, since in most regex dialects, \d is the same as [0-9]: But: do you really need 11 separate capturing groups? And if so, why don’t you capture the … Read more
Logical XOR operator in C++?
The != operator serves this purpose for bool values.
PowerShell and the -contains operator
The -Contains operator doesn’t do substring comparisons and the match must be on a complete string and is used to search collections. From the documentation you linked to: -Contains Description: Containment operator. Tells whether a collection of reference values includes a single test value. In the example you provided you’re working with a collection containing just one string … Read more