You have asked two questions that are not quite equivalent: Firstly, how to determine whether an array has only numeric keys Secondly, how to determine whether an array has sequential numeric keys, starting from 0 Consider which of these behaviours you actually need. (It may be that either will do for your purposes.) The first … Read more
The easiest way to convert a byte array to a stream is using the MemoryStream class: Stream stream = new MemoryStream(byteArray);
Yes. As of Swift 3.0, if you need the index for each element along with its value, you can use the enumerated() method to iterate over the array. It returns a sequence of pairs composed of the index and the value for each item in the array. For example: for (index, element) in list.enumerated() { … Read more
To get the first n elements of an array, use const slicedArray = array.slice(0, n);
Yes there is: ARRAY=() ARRAY+=(‘foo’) ARRAY+=(‘bar’) Bash Reference Manual: In the context where an assignment statement is assigning a value to a shell variable or array index (see Arrays), the ‘+=’ operator can be used to append to or add to the variable’s previous value. Also: When += is applied to an array variable using … Read more
There is a difference, but there is no difference in that example. Using the more verbose method: new Array() does have one extra option in the parameters: if you pass a number to the constructor, you will get an array of that length: x = new Array(5); alert(x.length); // 5 To illustrate the different ways … Read more
Just typecast it $array = (array) $yourObject; From Arrays: If an object is converted to an array, the result is an array whose elements are the object’s properties. The keys are the member variable names, with a few notable exceptions: integer properties are unaccessible; private variables have the class name prepended to the variable name; … Read more
for in loops over enumerable property names of an object. for of (new in ES6) does use an object-specific iterator and loops over the values generated by that. In your example, the array iterator does yield all the values in the array (ignoring non-index properties).
Use .bind() when you want that function to later be called with a certain context, useful in events. Use .call() or .apply() when you want to invoke the function immediately, and modify the context. Call/apply call the function immediately, whereas bind returns a function that, when later executed, will have the correct context set for … Read more
%w(foo bar) is a shortcut for [“foo”, “bar”]. Meaning it’s a notation to write an array of strings separated by spaces instead of commas and without quotes around them. You can find a list of ways of writing literals in zenspider’s quickref.