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Why do i have to dereference a reference (not a pointer) to access its data (context: used as parameter in STL-algorithm)? I'm writing a programm that's supposed to define classes that represent a sparse matrix (matrix with few non-zero values) and then perform a few operations on a vector of these sparse matrixes. The part where i had to define the classes mostly works (1) and there also already is a working vector of the matrices ("matrixvec") itself. However now i just want to add all the matrices together using the accumulate-algorithm from the STL. This works somewhat, but not really in the way i expected. So basically i give accumulate as an initial value an external matrix called "sammelmatrix" and then accumulate adds every matrix to "sammelmatrix" (using a self-defined +operator (that works in other parts of the programm too). Using this method (instead of e.g. "sammelmatrix = accumulate(...);") i think you would need to pass sam...

In javascript how does the below code works In Javascript how does the below code works. var a = { prop1: "a", prop2: "b", fun: function() { return this.prop1 + " " + this.prop2; } } var a2 = a; a.fn = "v"; a = {}; if (a === a2) { console.log(true); } else { console.log(false); } The above code prints false. But if I comment out the line a={} the value which prints on console is true. var a = { prop1: "a", prop2: "b", fun: function() { return this.prop1 + " " + this.prop2; } } var a2 = a; a.fn = "v"; //a={}; if (a === a2) { console.log(true); } else { console.log(false); } How the above code works, as Both variables(a and a2) points to the same object but when I initialized a with {} it gave false. In the first example a points to the assigned {} and a2 to the object a hold before {} was assigned to it. var a2=a; does not create an alias or r...