我正在使用Javascript来验证一些代码,并且它工作正常,但是每当我调用alert来显示错误时,在警报消息的开始处我都会得到'undefined'。因此,当我预计警报显示'请输入低目标'时,我会得到'未定义请输入低目标'。有人可以告诉我我的代码有什么问题吗?'undefined'出现在警报中
//validation
var lowTarget;
var highTarget;
var errorList;
var isValid = true;
lowTarget = $('input[name="txtLowTarget"]').val();
highTarget = $('input[name="txtHighTarget"]').val();
if (lowTarget == "") {
errorList += "Please enter a Low Target\n";
isValid = false;
}
else {
if (isNumeric(lowTarget) == false) {
errorList += "Low Target must be numeric\n";
isValid = false;
}
}
if (highTarget == "") {
errorList += "Please enter a High Target\n";
isValid = false;
}
else {
if (isNumeric(highTarget) == false) {
errorList += "High Target must be numeric\n";
isValid = false;
}
}
if (isValid == true) {
if (!(parseFloat(highTarget) > parseFloat(lowTarget))) {
errorList += "High Target must be higher than Low Target\n";
isValid = false;
}
}
if (isValid == false) {
alert(errorList);
}