var reg = /(.*?)<img.+?alt=('|")(.*?)2.*?>([^<]*)/gi;
var str = "你好<img src='aaa.gif' alt='图1'>天气不错<img src='bbb.gif' alt='图2'>哈哈"
var resultStr = ''
var exec = ''
while(exec = reg.exec(str)) {
resultStr += exec[1] + exec[3] + exec[4]
}
console.log(resultStr)
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…