：無效的：需要CSS僞類不使用jQuery遍歷方法時，選擇多個表單元素相匹配的工作

HTML：無效的：需要CSS僞類不使用jQuery遍歷方法時，選擇多個表單元素相匹配的工作

<input required> 
<input required> 
<input required>

的JavaScript

/* 
// Add script for noted :invalid check to work 
// :required can also be made to work by modifying script, i.e. changing "invalid" to "required" where noted 
// Source: http://stackoverflow.com/a/15821264/2171842 
jQuery.extend(jQuery.expr[':'], { 
    invalid : function(elem, index, match){ // modify pseudo-class here 
     var invalids = document.querySelectorAll(':invalid'), // modify pseudo-class here 
      result = false, 
      len = invalids.length; 

     if (len) { 
      for (var i=0; i<len; i++) { 
       if (elem === invalids[i]) { 
        result = true; 
        break; 
       } 
      } 
     } 
     return result; 
    } 
}); 
*/ 
$(document).ready(function(){ 
    // works 
    console.log("number of invalid elements: "+$(":invalid").length); // selector matches multiple elements 
    console.log("is first element invalid? "+$("input:first").is(":invalid")); // selector matches one element 
    console.log("is at least one element enabled? "+$("input").is(":enabled")); // selector matches multiple elements 
    // fails without additional script, :required also fails 
    console.log("is at least one element invalid? "+$("input").is(":invalid")) // selector matches multiple elements 
    console.log("number of invalid elements: "+$("input:first").siblings(":invalid").andSelf(":invalid").length) // selector (siblings(":invalid")) matches multiple elements 
});

控制檯錯誤：Uncaught Error: Syntax error, unrecognized expression: unsupported pseudo: invalid 。按照代碼中的註釋來導航問題。這是一個錯誤或只是在jQuery中不支持的功能？

小提琴

https://jsfiddle.net/cbqdp43s/

來源

2016-01-10 Jairo Contreras