5-2 惰性匹配

只会匹配第一个首字符

var  reg =/\d+/g
    var str = '3880376214'
    var arr = str.match(reg)
    console.log(arr);
    var reg2 = /\d+?/g
    var arr2 = str.match(reg2)
    console.log(arr2)