【leetcode】Valid Number

var isNumber = function(s) {
    s = s.replace(/(^\s*)|(\s*$)/g, "")
    //0
    if(s == ‘0‘){
        return true
    }
    if(s.replace(/\./g,"") == ""){
        return false
    }
    //不包括任何一个数字
    var re = /\d/
    if( !re.test(s) ){
        return false
    }
    //正负整数
    //var re = new RegExp(rs);
    re = /^[\+-]?[0-9]\d{0,}$/
    if( re.test(s) ){
        return true
    }

    //正负小数
    re = /^[\+-]?[0-9]?\d{0,}\.\d{0,}$|^[\+-]?0\.\d{0,}$/
    if( re.test(s) ){
        return true
    }
    // .1
    re = /^-?\.\d{1,}$/
    if( re.test(s) ){
        return true
    }

    //科学计数法
    //.e1 -> false; .2e1->true; 1.431352e7 ->true
    re = /^[\+-]?[0-9]+e[-\+]?\d{1,}$|^[\+-]?[0-9]+\.{1}e[-\+]?\d{1,}$|^[\+-]?\d*\.{1}\d+e[-\+]?\d{1,}$/
    if( re.test(s) ){
        return true
    }
    return false
};