The 'and' operator can refer to either a logical AND (evaluating to true if all the compared statements are true) or a bitwise AND (comparing the bits of an integer). For the latter use tag [bitwise-and].
Questions tagged [and-operator]
96 questions
324
votes
5 answers
Difference between Boolean operators && and & and between || and | in R
According to the R language definition, the difference between & and && (correspondingly | and ||) is that the former is vectorized while the latter is not.
According to the help text, I read the difference akin to the difference between an "And"…
Suraj
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86
votes
7 answers
Javascript AND operator within assignment
I know that in JavaScript you can do:
var oneOrTheOther = someOtherVar || "these are not the droids you are looking for...";
where the variable oneOrTheOther will take on the value of the first expression if it is not null, undefined, or false. In…
Alex
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78
votes
4 answers
Regex AND operator
Based on this answer
Regular Expressions: Is there an AND operator?
I tried the following on http://regexpal.com/ but was unable to get it to work. What am missing? Does javascript not support it?
Regex: (?=foo)(?=baz)
String: foo,bar,baz
user366735
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63
votes
7 answers
How does C++ handle &&? (Short-circuit evaluation)
When encountering a (bool1 && bool2), does c++ ever attempts to check bool2 if bool1 was found false or does it ignore it the way PHP does?
Sorry if it is too basic of a question, but I really could not find a mentioning of that neither in Schildt…
Aleksandrs Ulme
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46
votes
5 answers
What is "x && foo()"?
I saw somewhere else said,
x && foo();
is equal to
if(x){
foo();
}
I tested it and they really did the same thing.
But why? What exactly is x && foo()?
Derek 朕會功夫
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17
votes
2 answers
how can I use AND operator in IF statement in nginx?
I'm trying to cache the request based on the response header.
Right now my desire condition is if the response has both 2 headers client-device and client-location, then the response should be cached on nginx side
So I tried with this code
if…
zadops
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14
votes
10 answers
Does Java check all arguments in "&&" (and) operator even if one of them is false?
I have such code:
if(object != null && object.field != null){
object.field = "foo";
}
Assume that object is null.
Does this code result in nullPointerException or just if statement won't be executed?
If it does, how to refactor this code to be…
pixel
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14
votes
5 answers
Operator precedence for And/&& in Ruby
I have a question regarding the and/&&/= keywords in Ruby.
The ruby docs say that the precedence for the mentioned keywords is: (1)&&, (2)=, (3)and.
I have this snippet of code I wrote:
def f(n)
n
end
if a = f(2) and b = f(4) then
puts "1)…
Alon
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12
votes
3 answers
PHP: if !empty & empty
So i have this form..
With 2 fields. "Youtube" and "link" I want to do if you have filled in YouTube, it should do this:
if(!empty($youtube)) {
if ($pos === false) {
echo "Du skal indtaste youtube et URL, som starter med…
Karem
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11
votes
5 answers
Using & (bitwise AND operator) in Angular ng-if expressions
I can't get the & operator to work in an Angular ng-if expression (to use with some bit flags). Suppose we have some HTML like this:
If value equals 3, then the bitwise operation should return 2 and thus a true…
illeb
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7
votes
2 answers
redefine __and__ operator
Why I can't redefine the __and__ operator?
class Cut(object):
def __init__(self, cut):
self.cut = cut
def __and__(self, other):
return Cut("(" + self.cut + ") && (" + other.cut + ")")
a = Cut("a>0")
b = Cut("b>0")
c =…
Ruggero Turra
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6
votes
5 answers
Short-circuit evaluation via the AND operator in PHP
I'm trying to improve my coding ninja h4x skills, and I'm currently looking at different frameworks, and I have found sample code that's pretty hard to google.
I am looking at the FUEL framework used in a project.
The sample I don't understand is…
Jan Dragsbaek
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6
votes
4 answers
use of **and** operator within an **if statement**
I was directed to this website by a friend.
I am trying to use and in Delphi, but I seem to be doing something wrong. Is there something you need to put in uses?
I have the following code:
procedure TForm1.Button1Click(Sender:…
gerard
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6
votes
2 answers
R - Find all vector elements that contain all strings / patterns - str_detect grep
Sample data
files.in.path = c("a.4.0. name 2015 - NY.RDS",
"b.4.0. name 2016 - CA.RDS",
"c.4.0. name 2015 - PA.RDS")
strings.to.find = c("4.0", "PA")
I want the logical vector that shows all elements that…
LWRMS
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6
votes
3 answers
C Relational Operator Output
#include
void main()
{
int x = 1, y = 0, z = 5;
int a = x && y || z++;
printf("%d", z);
}
This yields output as 6 whereas
#include
void main()
{
int x = 1, y = 0, z = 5;
int a = x && y && z++;
…
Srijan Kumar
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