如何使用JavaScript读取CSS规则值？

以scunliffe的答案为基础：

function getStyle(className) {    var cssText = "";    var classes = document.styleSheets[0].rules || document.styleSheets[0].cssRules;    for (var x = 0; x < classes.length; x++) {     if (classes[x].selectorText == className) { cssText += classes[x].cssText || classes[x].style.cssText;        }  }    return cssText;}alert(getStyle('.test'));