javascript 检查数字字符串是否包含十进制？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/9838809/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
check if number string contains decimal?
提问by monkey blot
After doing a sqrt()
执行 sqrt() 后
How can I be check to see if the result contains only whole numbers or not?
如何检查结果是否仅包含整数？
I was thinking Regex to check for a decimal - if it contains a decimal, that means it didn't root evenly into whole numbers. Which would be enough info for me.
我在想 Regex 检查小数 - 如果它包含小数，那意味着它没有均匀地根植于整数。这对我来说已经足够了。
but this code isnt working...
但是这段代码不起作用......
result = sqrt(stringContainingANumber);
decimal = new RegExp(".");
document.write(decimal.test(result));
I bet there's other ways to accomplish the same thing though.
我敢打赌还有其他方法可以完成同样的事情。
回答by stefan bachert
. means any char. You have to quote the dot. "\."
. 表示任何字符。你必须引用点。“\。”
Or you could test
或者你可以测试
if (result > Math.floor(result)) {
// not an decimal
}
回答by pimvdb
You can use the %operator:
您可以使用%运算符：
result % 1 === 0; // rest after dividing by 1 should be 0 for whole numbers
回答by James Hill
回答by John Sobolewski
"." has meaning in the regex syntax which is "anything" you need to escape it using "\."
“。” 在正则表达式语法中具有含义，即您需要使用“\”将其转义的“任何东西”。
回答by Vatsal
If its a string we can just use split function and then check the length of the array returned. If its more than 1 it has decimal point else not :). This doesn't work for numbers though :(. Please see the last edit. It works for string as well now :)
如果它是一个字符串，我们可以使用 split 函数然后检查返回的数组的长度。如果它大于 1，它有小数点，否则没有:)。虽然这不适用于数字:(。请参阅最后一次编辑。它现在也适用于字符串:)
function checkDecimal() {
var str = "202.0";
var res = str.split(".");
alert(res.length >1);
var str1 = "20";
alert(str1.split(".").length>1);
}
Hope it helps someone. Happy Learning :)
希望它可以帮助某人。快乐学习:)
回答by samar ranjan Nayak
Are you looking for checking string containing decimal digits , you can try like this
您是否正在寻找检查包含十进制数字的字符串，您可以尝试这样
var num = "123.677";
if (!isNaN(Number(num)) {
alert("decimal no");
}
else {
alert("Not a decimal number");
}
