So the other day I had my colleague review my code and he saw that I was using array[0], in Java terms this is basically getting the first element of the array. I did this several times for different purposes, all of which is to get the first element in an array/collection, for example list.get(0), to which he strongly disagreed with.
His argument was that somebody from non-programming background would have problem understanding it and using 0 in such cases is basically hard-coding, which is bad practice. I google-ed several times and all suggestions to getting the first element in an array or any collection is providing them the index, which is 0 in this case.
Could anyone provide me with a suggestion on getting the first element in a meaningful way?
Try using linkedlist's getfirst method to get the first element of the list.
If you were to use an ArrayList is backed by an array and hence its perfectly valid to use index as 0 to get first element.
Related
I was coding in MPI using C. I don't understand how the MPI_Send() works or if maybe &array[element] works.
MPI_Send(&array[element],element_left,MPI_INT,i,0,MPI_COMM_WORLD);
here array[]={1,2,3,4,5,6,7,8,9,10} and element = 6 and element_left = 4. I understand array[element]=array[6]=7 but why this function picks 7,8,9,10? I know it will pick 4 elements from the array but why do we need & here and by only giving starting entry array[6] how is this function able to pick the next 3 as well?
I thought I have to add one after another using a for loop or something, but when I searched something on Google I got this code and after going through so much I still didn't understand. Please help me understand the backwardness of this code.
&array[element] is the same expression as array + element and means the address of the elementth element of the array array.
The function you call wants this address as the first argument, and takes the number of elements to process as the second argument.
Most MPI routines take a trio of arguments:
address of buffer
count of elements
datatype of elements
So by &array[element],element_left,MPI_INT you specify the elements element as the start of the buffer, and then you take element_left many integers to send. Kinda strange that you name the count element_left which is more like a name for an index, but that's what happens.
Sometimes you need to ng-if or ng-show an item in html based on some choices made earlier. One of these for me is "Additional Item". You can enter one set of information, and also if you want, an additional set. This creates an array of 2 similar objects. With this setup, you can only have 1 or 2 objects in this array. (important, since the scope of this question needs to be limited this way)
I want to ng-show an html directive based on "myItemsArray.length > 1". Since the array can (read should) only be 1 or 2 in length (not 0), this should work. However, it does not, because AngularJS seems to be adding an item "proto" to the array which adds to the count. See the image.
The problem is, proto makes the array length equal 2. I am not going to just look for length > 2 because i really don't know if i can count on proto always being there, and i just think thats bad practice anyway.
Also, i know there are MANY other ways of doing this (setting a boolean, or using another var to indicate etc, but i really just want to work with count of items in the array because "business logic"..
EDIT:
After doing a little debugging, i'm seeing that i have an array of "Object, undefined". How is this even possible :)
Some search lead me to this. Why are some values in my array undefined
EDIT:
Seems that using a delete may cause this problem
I'm having trouble with a clear statement. I've got an array that gets sized dynamically, filled, and then passed to a function to be converted to some custom objects.
After that conversion I want to clear the array. I use
Array.Clear(FileData, 0, FileData.Length)
as this thread suggests (reset-an-array-to-default-in-visual-basic). However, every time I get to that point in the script the try-catch wrapping the Clear catches an out of bounds exception on the Clear.
The array is not empty (actually it's got ~34900 items) so it's not that the array has zero length. The one thing that it might be that isn't discussed in the question I referenced above is that my array is 2 dimensional.
All that said, I'm fairly well stumped. Any help would be appreciated.
UPDATE: For those experiencing this issue, I ultimately just left the step commented out, so that instead of clearing and then setting the array to Nothing, I just set it to Nothing. Doesn't really solve the underlying issue, but (should) free up memory all the same.
Usually in protractor you can select singular element with:
element(protractor.By.css('#fdfdf'));
Occasionally you get something like this:
element(protractor.By.css('.dfdf'));
which potentially has more than one element. What's the correct way to select an index from a locator that locates multiple elements, and still contain the protractor's methods for sending Keys?
You can get an indexed element from an array returned with
// Get the 5th element matching the .dfdf css selector
element.all(by.css('.dfdf')).get(4).sendKeys('foo');
If you want to get the first element then
element.all(by.css('.dfdf')).first();
element.all(by.css('.dfdf')).get(0);
Try this one. It will work:
element.all(by.css('.dfdf')).get(4).getText();
I don't know why xpath is so much underestimated but you can solve thousands of problems with it, including this one
let elem = element(by.xpath('(//div//a)[3]'))
You can specify the number of element to use. Keep in mind the numbers start from 1, not 0 as usually in js
I am working with an older and undocumented set of ActionScript (AS2) and I have found that an array, when looping through it the second time, does not give the proper results. It has been a while since I used ActionScript - does the array need to be reset before the second time through another for loop?
For instance PHP has reset() which returns the array's pointer back to the first item in the array.
There's is no such thing as pointers in ActionScript.
You can target each and every item in an Array by simply targeting it with myArray[index], and no pointer needs to be reset to be able to re-read it.
If your two loops produce different results, I would suggest looking into code that could change anything in it between the two loops or in the first one.
Maybe you could post it here ?