arrays

问题 What's the best method to get the index of an object in an object array given multiple of it's properties? Imagine the following example array: var array = [ { color: 'red', shape: 'square', weight: 200 }, { color: 'blue', shape: 'circle', weight: 300 }, { color: 'red', shape: 'circle', weight: 100 } ]; Now I would like to have the indexOf the object which color property is red and shape is circle which, in this example, would be 2 . Ideally the function would return the index of the object

问题 What's the best method to get the index of an object in an object array given multiple of it's properties? Imagine the following example array: var array = [ { color: 'red', shape: 'square', weight: 200 }, { color: 'blue', shape: 'circle', weight: 300 }, { color: 'red', shape: 'circle', weight: 100 } ]; Now I would like to have the indexOf the object which color property is red and shape is circle which, in this example, would be 2 . Ideally the function would return the index of the object

问题 I have an array sorting function as follows: public function sortAscending($accounts) { function ascending($accountA, $accountB) { if ($accountA['AmountUntilNextTarget'] == $accountB['AmountUntilNextTarget']) { return 0; } return ($accountA['AmountUntilNextTarget'] < $accountB['AmountUntilNextTarget']) ? -1 : 1; } usort($accounts, $ascending); return $accounts; } Clearly this is not ideal as it is hard-coding the key to search for. I thought I would make this generic by passing the key as a

问题 Why can't we declare an array of 10000000 integers (or say, large enough) inside the main function or inside any function locally while it is possible globally? 回答1: tl;dr: space for local variables is limited. That's how CPU's and Operating Systems work. This is an implementation detail that is shared by many languages and implementations, e.g. C, C++ on typical desktop OS. Most platforms where the code runs on set aside some memory called the Stack to be used for return adresses and local

问题 I wanted to print the values of selected checkboxes instead of "Custom Category". I have tried to get value, attribute but not getting the values. I wanted to print the values of the selected checkbox. app.component.html <form #myForm="ngForm"> <div class="form-group"> <div class="form-check form-check-inline"> <input class="form-check-input" type="checkbox" id="dl1" required #dl="ngModel" value="DL1" ngModel name="dl"> <label class="form-check-label" for="">DL 1</label> </div> <div class=

问题 The function below is supposed compute either the Uval and Lval functions in accordance to Set and Numbers . For the first two numbers U and 52599 are in relation and L and 52550 are in relation, since the second number has the label L the Lval equation is used. The previous number is function is previous = numbers[1:] and the current function is current = numbers[:-1] . So (52550 - 52599)/52550 * -100 will be the computation for the first two numbers. The equations are supposed to be

问题 The function below is supposed compute either the Uval and Lval functions in accordance to Set and Numbers . For the first two numbers U and 52599 are in relation and L and 52550 are in relation, since the second number has the label L the Lval equation is used. The previous number is function is previous = numbers[1:] and the current function is current = numbers[:-1] . So (52550 - 52599)/52550 * -100 will be the computation for the first two numbers. The equations are supposed to be

问题 I have array that I need to sort by another array form 2 fields zip code and approve I am able to sort it by zip code but unable to do it with approved field so for eg I need to sort by 60007,60001,60003,60002 (as per sortlike order) all zip code from 60007 and approved should come first so $sortLike=array(60007,60001,60003,60002); $array1= array( array ('ID' => 138,'zip_code' => 60007,'approved' => 1), array('ID' => 103,'zip_code' => 60007,'approved' => 0), array('ID' => 114,'zip_code' =>

问题 I'm trying to write a method for 'transpose' a two-dimensional array of integers, in which the rows and columns of the original matrix are exchanged. However, I have no idea how I can realize this. How do I write out this method? public class Matrix { private int[][] numbers; public Matrix(int rows, int colums) { if (rows < 1) rows = 1; else rows = rows; if (colums < 1) colums = 1; else colums = colums; numbers = new int[rows][colums]; } public final void setNumbers(int[][] numbers) { this

问题 I am trying to de-reference the 2D array inside the function islandPerimeter . But I cannot understand why I am getting segfault for this. Can someone point out what exactly I am doing wrong? update: So this was a part of a problem from leetcode I was trying to solve.I now understand it is not 2D array but a pointer. I am still confused over the int**. can someone explain it? #include <stdio.h> int islandPerimeter(int** grid, int gridSize, int gridColSize) { int perimeter=0,points=4,i=0; for