loops

问题 This question already has answers here : Add a property to a JavaScript object using a variable as the name? (13 answers) Closed 4 years ago . Assuming I've a JSON object like this: var myObj = { 'question1': { 'option1': 'foo', 'option2': 'bar', 'option3': 'baz' }, 'question2': { ... }, 'question3': { ... } }; And since its children always has a number in its keys, I want to do a loop and concatenate the loop's index to the object keys, and get the values in the dot notation method... So, I

问题 Here is the homework assignment I'm trying to solve: A further improvement of the approximate integration method from the last question is to divide the area under the f(x) curve into n equally-spaced trapezoids. Based on this idea, the following formula can be derived for approximating the integral: !(https://www.dropbox.com/s/q84mx8r5ml1q7n1/Screenshot%202017-10-01%2016.09.32.png?dl=0)! where h is the width of the trapezoids, h=(b−a)/n , and xi=a+ih,i∈0,...,n , are the coordinates of the

问题 Here is the homework assignment I'm trying to solve: A further improvement of the approximate integration method from the last question is to divide the area under the f(x) curve into n equally-spaced trapezoids. Based on this idea, the following formula can be derived for approximating the integral: !(https://www.dropbox.com/s/q84mx8r5ml1q7n1/Screenshot%202017-10-01%2016.09.32.png?dl=0)! where h is the width of the trapezoids, h=(b−a)/n , and xi=a+ih,i∈0,...,n , are the coordinates of the

问题 Firstly, I know it would be more simple to achieve this using CSS but I am really trying to wrap my head around looping with JS as it is a new concept for me What I want to happen is for the 'bg' class to loop through a number of background colours once My code does not currently work would very much appreciate some direction :) HTML <div class="bg"></div> CSS .bg { width: 100%; height: 100%; } JS var bg = document.getElementByClassName('bg'); var colours = ["#CCCDFF", "#BAC7E8", "#D9EEFF", "

问题 Using jquery, I want to loop all elements having the class "item" and apply different background colors according to the index of the element. mapcolor is an array of colors (length = number of elements having "item" class) $.each($(".item"), function(i,e){ $("#"+e).css("background-color",mapcolor[i]); }); $("#"+e) selector doesn't work as expected, neither $("#"+e.id) ... Something's wrong with my selector. Any idea? 回答1: use .each() method instead and you have to be in the context with $

问题 I have a for loop nested in another for loop. How can I make it so that when somethign happens in the inner loop, we exit and jump to the next iteration of the outer loop? uuu <- 0 for (i in 1:100) { uuu <- uuu + 1 j <- 1000 for (eee in 1:30) { j <- j - 1 if (j < 990) { # if j is smaller than 990 I hope start next time of i } } } 回答1: @flodel has the correct answer for this, which is to use break rather than next . Unfortunately, the example in that answer would give the same result whichever

问题 Im new to python, or coding for that matter... This part of the code allows me to find all the elements that I want to click (click on the link open a new tab) from selenium import webdriver import time driver = webdriver.Chrome() driver.get("http://www.rezultati.com/kosarka/filipini/kup/") list_of_links = driver.find_elements_by_css_selector(".cell_ad.time") for link in list_of_links: link.click() Obviously this for loop only opens links.. I'm interested in how to add, somethin like this, to

问题 Im new to python, or coding for that matter... This part of the code allows me to find all the elements that I want to click (click on the link open a new tab) from selenium import webdriver import time driver = webdriver.Chrome() driver.get("http://www.rezultati.com/kosarka/filipini/kup/") list_of_links = driver.find_elements_by_css_selector(".cell_ad.time") for link in list_of_links: link.click() Obviously this for loop only opens links.. I'm interested in how to add, somethin like this, to

问题 Im new to python, or coding for that matter... This part of the code allows me to find all the elements that I want to click (click on the link open a new tab) from selenium import webdriver import time driver = webdriver.Chrome() driver.get("http://www.rezultati.com/kosarka/filipini/kup/") list_of_links = driver.find_elements_by_css_selector(".cell_ad.time") for link in list_of_links: link.click() Obviously this for loop only opens links.. I'm interested in how to add, somethin like this, to

问题 I'm wondering why my code doesn't play the loop for the video. Everything is working except the loop option. And I really need it. Thanks a lot. <script src="jsapi.js"></script> <script src="swfobject.js"></script> <div id="ytapiplayer">You need Flash player 8+ and JavaScript enabled to view this video.</div> <script type="text/javascript"> google.load("swfobject", "2.1"); function onYouTubePlayerReady(playerId) { ytplayer = document.getElementById("myytplayer"); ytplayer.playVideo();