Yes, they’re not the same. var a = b = [] is equivalent to var a; b = []; a = b; Not only do both a and b get assigned the same value (a reference to the same empty array), b is not declared at all. In strict mode in ECMAScript 5 and later, … Read more
You don’t. This is a language feature to prevent the standard unwanted side-effect of assignment returning a value, as described in the Swift book: Unlike the assignment operator in C and Objective-C, the assignment operator in Swift does not itself return a value. The following statement is not valid: if x = y { // … Read more
It’s a chain of assignments and the term used to describe it is… – Could I get a drumroll please? Chained Assignment. I just gave it a quite google run and found that there isn’t that much to read on the topic, probably since most people find it very straight-forward to use (and only the … Read more
The struct1=struct2; notation is not only more concise, but also shorter and leaves more optimization opportunities to the compiler. The semantic meaning of = is an assignment, while memcpy just copies memory. That’s a huge difference in readability as well, although memcpy does the same in this case. Use =.
You have to replace the item, not the value of customListItem2. Just replace following: customListItem2 = customListItems.Where(i=> i.name == “Item 2”).First(); customListItem2 = newCustomListItem; With this: customListItem2 = customListItems.Where(i=> i.name == “Item 2”).First(); var index = customListItems.IndexOf(customListItem2); if(index != -1) customListItems[index] = newCustomListItem; Edit: As Roman R. stated in a comment, you can replace the … Read more
This isn’t simply “multiple variable assignment”, it’s fully-featured pattern matching! So the following are all valid: val (a, b) = (1, 2) val Array(a, b) = Array(1, 2) val h :: t = List(1, 2) val List(a, Some(b)) = List(1, Option(2)) This is the way that pattern matching works, it’ll de-construct something into smaller parts, … Read more
No, it’s a common practice. It’s only considered bad style for expressions that are considerably longer than yours.
The language guarantees that int is at least 16 bits, long is at least 32 bits, and long can represent at least all the values that int can represent. If you assign a long value to an int object, it will be implicitly converted. There’s no need for an explicit cast; it would merely specify … Read more
foo.x = foo = {n: 2}; determines that foo.x refers to a property x of the {n: 1} object, assigns {n: 2} to foo, and assigns the new value of foo – {n: 2} – to the property x of the {n: 1} object. The important thing is that the foo that foo.x refers to … Read more
Python’s generator expressions are late binding (see PEP 289 — Generator Expressions) (what the other answers call “lazy”): Early Binding versus Late Binding After much discussion, it was decided that the first (outermost) for-expression [of the generator expression] should be evaluated immediately and that the remaining expressions be evaluated when the generator is executed. […] … Read more