如下所示:
var str = 'abcadeacf'
var str1 = str.replace('a', 'o')
alert(str1)
// 结果: obcadeacf
var str2 = str.replace(/a/g, 'o')
alert(str2)
//结果: obcodeocf,
let str='asdfsd<span>aaaa234</span>fdsad2342332'str=str.split('<span>').map(function(e){
let a=e.split('</span>')
a[a.length-1]=a[a.length-1].replace(/a/g,'<span>2222</span>')
return a.join('</span>')
}).join('<span>')
console.log(str)