selectors-api

问题 This question already has answers here : What do querySelectorAll and getElementsBy* methods return? (10 answers) Closed 12 days ago . I understand that under normal circumstances, you would use querySelector to select a single element and querySelectorAll for multiple. However, I was surprised to discover that querySelectorAll doesn't work with a single element. I expected it to work with one OR more. I can't find anything that says it shouldn't work with just one so I'm asking here if that

问题 I ran across some JS code using the following to select the first of multiple nodes. querySelectorAll()[0] Isn't the following doing the exact same thing? querySelector() Is there an advantage of using querySelectorAll()[0] ? 回答1: Both expressions will return the exact same result. The only difference is the querySelectorAll()[0] will first find all the items that match the selector and then index the first item. Whereas querySelector() will "short circuit" once it finds the first element. So

问题 I ran across some JS code using the following to select the first of multiple nodes. querySelectorAll()[0] Isn't the following doing the exact same thing? querySelector() Is there an advantage of using querySelectorAll()[0] ? 回答1: Both expressions will return the exact same result. The only difference is the querySelectorAll()[0] will first find all the items that match the selector and then index the first item. Whereas querySelector() will "short circuit" once it finds the first element. So

问题 This question already has answers here : Selecting and manipulating CSS pseudo-elements such as ::before and ::after using jQuery (22 answers) How to update placeholder color using Javascript? (3 answers) Closed 2 months ago . Is it possible to change a CSS pseudo-element style via JavaScript? For example, I want to dynamically set the color of the scrollbar like so: document.querySelector("#editor::-webkit-scrollbar-thumb:vertical").style.background = localStorage.getItem("Color"); and I

问题 I am trying to find a way to build the querySelector string of any given node. In other words - pick any node on a page - is it possible to walk up the DOM and build a string that would allow me to pass the generated string to document.querySelector and get back the node I chose? From what I can tell querySelector has a bug where you can only use nth-child once in the string. I have tried several times but so far have failed to find a solution. I want to do this in native JavaScript, not

问题 Does querySelectorAll support the period(.) character in an id? I mean if I append an element like below: var div = document.createElement('div'); div.id='my.divid'; document.body.appendChild(div); and then I use querySelectorAll like below: document.querySelectorAll('#my.divid'); then I get nothing! So period is legal character for id, and querySelectorAll is the official method which Firefox provided; I can't believe the method doesn't support period(.) in id. Did I make some mistake? 回答1:

问题 Does querySelectorAll support the period(.) character in an id? I mean if I append an element like below: var div = document.createElement('div'); div.id='my.divid'; document.body.appendChild(div); and then I use querySelectorAll like below: document.querySelectorAll('#my.divid'); then I get nothing! So period is legal character for id, and querySelectorAll is the official method which Firefox provided; I can't believe the method doesn't support period(.) in id. Did I make some mistake? 回答1:

问题 I have just started using querySelector . I want to get the text data of first non empty element without concerning the element name (p or div or span). For example: 1) <div> <span></span> <span>data</span> <span>data1</span> <div> 2) <div> <ul> <li></li> <li>data</li> </ul> <span>data1</span> <div> In both the cases I want to get the text data of first element that is non empty. In 1 case from the second span and in 2 case from the second li . Is that possible? 来源： https://stackoverflow.com

问题 Reference answer: https://stackoverflow.com/a/38399344/5132413 Please refer my question and the answer linked above works only in Firefox, Chrome, and Opera. I did some research and found that it (case insensitivity flag) isn't compatible. I need an equivalent in IE, Edge and Safari. var divs = document.querySelectorAll('div[class^="foo" i]'); 回答1: Since css level 4 is still in drafts, case-sensitivity selector is not compatible with most browsers. You may use filter method like this: var

问题 Reference answer: https://stackoverflow.com/a/38399344/5132413 Please refer my question and the answer linked above works only in Firefox, Chrome, and Opera. I did some research and found that it (case insensitivity flag) isn't compatible. I need an equivalent in IE, Edge and Safari. var divs = document.querySelectorAll('div[class^="foo" i]'); 回答1: Since css level 4 is still in drafts, case-sensitivity selector is not compatible with most browsers. You may use filter method like this: var