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When is JavaScript's eval() not evil?
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I'd like to take a moment to address the premise of your question - that eval() is "evil". The word "evil", as used by programming language people, usually means "dangerous", or more precisely "able to cause lots of harm with a simple-looking command". So, when is it OK...
What is the difference between currying and partial application?
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Currying is converting a single function of n arguments into n functions with a single argument each. Given the following function:
function f(x,y,z) { z(x(y));}
When curried, becomes:
function f(x) { lambda(y) { lambda(z) { z(x(y...
How expensive is the lock statement?
...rallel processing and I needed a counter to do some basic counting and statistic analysis of the speed of the processing. To avoid problems with concurrent use of my class I've used a lock statement on a private variable in my class:
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What's the difference between equal?, eql?, ===, and ==?
...t to try these out for yourself on different objects, use something like this:
class Object
def all_equals(o)
ops = [:==, :===, :eql?, :equal?]
Hash[ops.map(&:to_s).zip(ops.map {|s| send(s, o) })]
end
end
"a".all_equals "a" # => {"=="=>true, "==="=>true, "eql?"=>true, "e...
What is a stream?
What is a stream in the programming world? Why do we need it?
6 Answers
6
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Does PHP have threading?
I found this PECL package called threads , but there is not a release yet. And nothing is coming up on the PHP website.
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What is the difference between atomic and critical in OpenMP?
What is the difference between atomic and critical in OpenMP?
8 Answers
8
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&& (AND) and || (OR) in IF statements
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No, it will not be evaluated. And this is very useful. For example, if you need to test whether a String is not null or empty, you can write:
if (str != null && !str.isEmpty()) {
doSomethingWith(str.charAt(0));
}
or, the other way around
if (str =...
What is a NullPointerException, and how do I fix it?
...e where you declare a variable of primitive type int:
int x;
x = 10;
In this example, the variable x is an int and Java will initialize it to 0 for you. When you assign it the value of 10 on the second line, your value of 10 is written into the memory location referred to by x.
But, when you try to...
What is the instanceof operator in JavaScript?
The instanceof keyword in JavaScript can be quite confusing when it is first encountered, as people tend to think that JavaScript is not an object-oriented programming language.
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