js 代码摘录

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获取子字符串

var myString = "Every good boy does fine.";var section = myString.substring(0, 10);    // section is now "Every good"----------var myString = "Every good boy does fine.";var section = myString.slice(11, -6);    // section is now "boy does"----------var myString = "Every good boy does fine.";var section = myString.substr(6, 4);    // section is now "good"

大小写转换

var myString = "New York";var lcString = myString.toLowerCase();var ucString = myString.toUpperCase();----------myString = myString.toLowerCase();----------

获取处理事件的事件源

function handleClick(evt) {   var evt = (evt) ? evt : ((window.event) ? window.event : null);   if (evt) {       var elem = (evt.target) ? evt.target : ((evt.srcElement) ? evt.srcElement : null);       if (elem && elem.id.indexOf("menuImg") == 0) {           // process events from elements whose IDs begin with "menuImg"       }   }}

获取指定字符在整个字符串中出现的次数

function countInstances(mainStr, srchStr) {    var count = 0;    var offset = 0;    do {        offset = mainStr.indexOf(srchStr, offset);        count += (offset != -1) ? 1 : 0;    } while (offset++ != -1)    return count}

使用正则表达式查找字符串

var longString="Framistan 2000 abc Framistan 2000 2 ...";var shortStr = "Framistan 2000";var re = new RegExp(shortStr, "g");var result = longString.match(re);if (result) {    alert("Found " + result.length + " instances of the text: " + result[0]);} else {    alert("Sorry, no matches.");}