Javascript 如何测试 NaN？
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How do I test for NaN?
提问by I wrestled a bear once.
Possible Duplicate:
Comparing NaN values for equality in Javascript
Can anyone tell me why this is not working?
谁能告诉我为什么这不起作用？
if(inbperr == NaN) {
document.getElementById('inbclo').value = "N/A";
}
else {
document.getElementById('inbclo').value = "%" + inbperr;
}
Instead of returning a percentage value, or "N/A", I want it to return "%NaN".
我希望它返回“%NaN”，而不是返回百分比值或“N/A”。
回答by Ned Batchelder
NaN's are unusual: they are not equal to anything, even themselves. You need to use isNaN(inbperr)to tell whether a value is a NaN or not.
NaN's 是不寻常的：他们不等于任何东西，甚至他们自己。您需要使用isNaN(inbperr)来判断一个值是否为 NaN。
回答by CoR
NaN is Not a Number. One of few JavaScript toxic types. It can reduce whole expression to NaN.
NaN 不是数字。少数 JavaScript 有毒类型之一。它可以将整个表达式简化为 NaN。
