object

问题 This is a javascript object. How can I get the count of elements with condition gallery="Abstract" and gallery="Game" . window.paintings = { 1: { id: 1, name: 'Abstract 1', gallery: 'Abstract', src:'Image64.jpg' }, 2: { id: 2, name: 'Abstract 2', gallery: 'Abstract', src:'Image65.jpg' }, 3: { id: 3, name: 'Abstract 3', gallery: 'Abstract', src:'Image66.jpg' }, 4: { id: 1, name: 'Game 1', gallery: 'Game', src:'Image66.jpg' }, 5: { id: 2, name: 'Game 2', gallery: 'Game', src:'Image66.jpg' }, };

问题 I am trying to find not just the closest point, but the 3 closest points in an array of 5 object points. I have tried several experiments using just a distance( d ) variable for each point. But I cannot figure out how to iterate through each point, compare it to the other points using the Pythagorean Theorem/Distance formula, and then find the closest 3. If the array has 5 points, I am guessing I need to store the results of each iteration in an array with a distance ( d ) value, sort by the

问题 I'm new to Javascript and I'm having some issues creating a feature. I have an html form which takes in users name and address. I want to create a function that when the user submits the form that users information is saved into a JavaScript object. Something like this: Var person = { Name : abc, Address: xyz} I was able to save the information into an object but when ever a new person submits the form the old info is overwritten. Is it possible to create a separate object for every user who

问题 I want that the x-position (=d_in) of my object (the Ellipse) is changed by changing the slider d_in. This is what I got: from numpy import pi, sin import numpy as np import matplotlib.pyplot as plt from matplotlib.widgets import Slider, Button, RadioButtons from matplotlib.patches import Ellipse from scipy.optimize import fsolve import pylab axis_color = 'lightgoldenrodyellow' #variable d_in=80 fig = plt.figure(figsize=(12,6)) ax = fig.add_subplot(111) fig.subplots_adjust(left=0.25, bottom=0

问题 I created an object which contains data fields of the types ImageView, boolean and Integer. public class MemoryCard implements View.OnClickListener, Serializable { private ImageView image; private int id; private int nr; private boolean clicked = false; private int cardBack; private int cardFront; public MemoryCard(Context context, int id, int nr, int cardFront) { this.id = id; this.nr = nr; this.cardBack = R.drawable.backside; this.cardFront = cardFront; this.image = new ImageView(context);

问题 I am fairly new to JS and I am having a bit trouble in understanding how to properly implement the callback passed to setState in React, for a controlled input. The following code is what I have so far: class App extends React.Component { ... this.state = { properties: { width: '', height: '' } this.handleChange = this.handleChange.bind(this); //edit 1 } handleChange(e){ this.setState(() => ({ properties[e.target.name]: e.target.value })) //edit 2 } render(){ return( <input type="text" value=

问题 I've got a small problem. I want to read a var defined inside tag in DOM. <script id="foo"> var x = 1 </script> I can access it via: var script = document.querySelector("#foo"); But then what? Of course var x_value = script.x or var x_value = script.outerHTML.x doesn't work. So how can I get x's value then? Thanks for your help! 回答1: Content script runs in isolated world so it cannot access the page variables directly. a literal numeric value can be extracted with a regexp: var scriptText =

问题 I worked on this all day and am stuck on my logic in how I approached this problem. Whenever I have a Vector<class> blah . And I try to blah.push_back(class()) , it doesn't, update or work. I've been researching and I think it has to do with pointers and references. I tried changing Vector<Student> blah to Vector<Student*> blah , and using 'new' Student() when I'm pushing it back, but it still yields the same result. I think I'm defining the vectors wrong. #include "std_lib_facilities.h"

问题 I want to create a class that automatically adds a holder for values that I can access in the future so that when I run cd.orders or cd.users it will return or give me a dataframe of each of the tables I just queried against. Heres my sample code: class samplecode: def __init__(self,credentials): c = credentials ('DATABASE', 'USER', 'PASSWORD', 'HOST', 'PORT', 'SCHEMA') print('credentials loaded') self.connection_string = "postgresql://%s:%s@%s:%s/%s" % (c.USER, c.PASSWORD, c.HOST, str(c.PORT

问题 I've got a list of object files that I want to package in a library. How do I do this? I thought I could use ADD_LIBRARY 回答1: add_library is the correct answer. To make a static library, you want to do something like this: add_library(foo STATIC foo.c bar.c baz.c) 回答2: Static libraries are becoming a bit obsolete, but "ar" is the command you are looking for. 来源： https://stackoverflow.com/questions/3974415/using-cmake-to-link-object-files-into-lib-xxxx-a-file