正则表达式 exec 与 match

exec

var reg = /^[+-]?(\d|([1-9]\d+))(\.\d+)?$/;// 是否为有效数字的正则，多位数，第一位不能为 0；
var str1 = "1255552.3",
    str2="2345",
    str3="0";
var ary = [];
var res = reg.exec(str1);
console.log(reg.test(str1),reg.test(str2),reg.test(str3));
console.log("exec str1",reg.exec(str1));//["1255552.3", "1255552", "1255552", ".3", index: 0, input: "1255552.3"]
console.log("exec str2",reg.exec(str2));//["2345", "2345", "2345", undefined, index: 0, input: "2345"]
console.log("exec str3",reg.exec(str3));//["0", "0", undefined, undefined, index: 0, input: "0"]

match

var reg = /^[+-]?(\d|([1-9]\d+))(\.\d+)?$/;// 是否为有效数字的正则，多位数，第一位不能为 0；
var str1 = "1255552.3",
    str2="2345",
    str3="0";
ary = str1.match(reg);
console.log(ary);//["1255552.3", "1255552", "1255552", ".3", index: 0, input: "1255552.3"]