将支付宝发来的数据生成有序数列

//将支付宝发来的数据生成有序数列
function getVerifyParams(params) {
    var sPara = [];
    if(!params) return null;
    for(var key in params) {
        if((!params[key]) || key == "sign" || key == "sign_type") {
            continue;
        };
        sPara.push([key, params[key]]);
    }
    sPara = sPara.sort();
    var prestr = '';
    for(var i2 = 0; i2 < sPara.length; i2++) {
        var obj = sPara[i2];
        if(i2 == sPara.length - 1) {
            prestr = prestr + obj[0] + '=' + obj[1] + '';
        } else {
            prestr = prestr + obj[0] + '=' + obj[1] + '&';
        }
    }
    return prestr;
}