Javascript 求和返回NaN
我有一个很蹩脚的问题。但我不知道怎么解决它 我试图在一个循环中添加两个float numberseg:1.0583389964654335,长度为1500Javascript 求和返回NaN,javascript,nan,Javascript,Nan,我有一个很蹩脚的问题。但我不知道怎么解决它 我试图在一个循环中添加两个float numberseg:1.0583389964654335,长度为1500 var distance = 0; for(var i = 0;i< latArray.length;i++) { var s = GCDistance(latArray[i],lonArray[i],latArray[i+1],lonArray[i+1]); distance =
var distance = 0;
for(var i = 0;i< latArray.length;i++)
{
var s = GCDistance(latArray[i],lonArray[i],latArray[i+1],lonArray[i+1]);
distance = parseFloat(distance) + parseFloat(s);
alert(distance);
}
var radius = 6378137.0 ; // earth radius
var DE2RA = 0.01745329252; // degre to radian conversion
GCDistance= function (lat1, lon1, lat2, lon2) {
//console.log(lat1, lon1, lat2, lon2);
if (lat1 == lat2 && lon1 == lon2) return 0;
lat1 *= DE2RA;
lon1 *= DE2RA;
lat2 *= DE2RA;
lon2 *= DE2RA;
var d = Math.sin(lat1) * Math.sin(lat2) + Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2);
if(isNaN(radius * Math.acos(d)))
{
console.log(lat1, lon1, lat2, lon2);
}
//console.log((radius * Math.acos(d)));
return (radius * Math.acos(d));
};
最初,警报返回数字。在某个极限后,它变为NaN。我想你已经越过了这个范围 范围为:+/-9007199254740992
你可以试试这个,只得到数字和
var distance = 0;
for(var i = 0;i< (latArray.length-1);i++)
{
var s = GCDistance(latArray[i],lonArray[i],latArray[i+1],lonArray[i+1]);
distance = parseFloat(distance) + parseFloat(s);
alert(distance);
}
注意:确保latArray、Onarray、latArray和Onarray中存在值,或者至少有一个问题可能是juvian评论中指出的问题: latArray[i+1]将[导致未定义]在最后一个索引[…] 在数学表达式中使用未定义的值时,会将其转换为NaN。然后,此NaN将通过其余的数学操作传播 下面是这种行为的演示
var x = +undefined // NaN -> x, as +expr results in [ToNumber(expr)]
2 + x // 2 + NaN -> NaN, as NaN "contaminates" every math operator
建议只循环到i
var x = +undefined // NaN -> x, as +expr results in [ToNumber(expr)]
2 + x // 2 + NaN -> NaN, as NaN "contaminates" every math operator