Properties cannot be passed by reference. Here are a few ways you can work around this limitation. 1. Return Value string GetString(string input, string output) { if (!string.IsNullOrEmpty(input)) { return input; } return output; } void Main() { var person = new Person(); person.Name = GetString(“test”, person.Name); Debug.Assert(person.Name == “test”); } 2. Delegate void GetString(string … Read more
It’s by value according to the PHP Documentation. By default, function arguments are passed by value (so that if the value of the argument within the function is changed, it does not get changed outside of the function). To allow a function to modify its arguments, they must be passed by reference. To have an … Read more
For the second part of your question, see the array page of the manual, which states (quoting) : Array assignment always involves value copying. Use the reference operator to copy an array by reference. And the given example : <?php $arr1 = array(2, 3); $arr2 = $arr1; $arr2[] = 4; // $arr2 is changed, // … Read more
Objects aren’t passed at all. By default, the argument is evaluated and its value is passed, by value, as the initial value of the parameter of the method you’re calling. Now the important point is that the value is a reference for reference types – a way of getting to an object (or null). Changes … Read more
Pass a ref if you want to change what the object is: TestRef t = new TestRef(); t.Something = “Foo”; DoSomething(ref t); void DoSomething(ref TestRef t) { t = new TestRef(); t.Something = “Not just a changed t, but a completely different TestRef object”; } After calling DoSomething, t does not refer to the original … Read more
There is no “pass by reference” available in JavaScript. You can pass an object (which is to say, you can pass-by-value a reference to an object) and then have a function modify the object contents: function alterObject(obj) { obj.foo = “goodbye”; } var myObj = { foo: “hello world” }; alterObject(myObj); alert(myObj.foo); // “goodbye” instead … Read more
My understanding is that this is actually very simple: Javascript is always pass by value, but when a variable refers to an object (including arrays), the “value” is a reference to the object. Changing the value of a variable never changes the underlying primitive or object, it just points the variable to a new primitive … Read more
The callback is passed the element, the index, and the array itself. arr.forEach(function(part, index, theArray) { theArray[index] = “hello world”; }); edit — as noted in a comment, the .forEach() function can take a second argument, which will be used as the value of this in each call to the callback: arr.forEach(function(part, index) { this[index] … Read more
Stop a Variable’s Reassignment While these answers are intellectually interesting, I’ve not read the short simple answer: Use the keyword final when you want the compiler to prevent a variable from being re-assigned to a different object. Whether the variable is a static variable, member variable, local variable, or argument/parameter variable, the effect is entirely … Read more
Primitives are passed by value, and Objects are passed by “copy of a reference”. Specifically, when you pass an object (or array) you are (invisibly) passing a reference to that object, and it is possible to modify the contents of that object, but if you attempt to overwrite the reference it will not affect the … Read more