[英]Checking the number inside a string in javascript
I have a string, say 我有绳子说
var Str = 'My name is 123 and my name is 234'
. var Str = 'My name is 123 and my name is 234'
。
Now I split this as 现在我将其拆分为
var arrStr = Str.split(' ');
I iterate through the array and have different logic depending upon whether the word is a string or number. 我遍历数组,并根据单词是字符串还是数字来使用不同的逻辑。 How do i check that?
我该如何检查? I tried
typeof
which didn't work for me. 我尝试了对我不起作用的
typeof
。
EDIT: 编辑:
After Seeing multiple answers. 看到多个答案之后。 Now, I am in despair, which is the most efficient way?
现在,我感到绝望,这是最有效的方法?
If you care only about the numbers, then instead of using split you can use a regular expression like this: 如果只关心数字,则可以使用如下正则表达式来代替使用split:
var input = "My name is 123 and my name is 234";
var results = input.match(/\d+/g)
If you care about all pieces, then you can use another expression to find all non-space characters like this: 如果您关心所有部分,则可以使用另一个表达式查找所有非空格字符,如下所示:
var input = "My name is 123 and my name is 234";
var results = input.match(/\S+/g)
Then iterate them one by one, and check if a given string is a number or not using the famous isNumeric()
function posted by @CMS in this famous question . 然后一个接一个地迭代它们,并使用@CMS在此著名问题中发布的著名 isNumeric
isNumeric()
函数检查给定的字符串是否为isNumeric()
。
function isNumber(n) {
return !isNaN(parseFloat(n)) && isFinite(n);
}
NOTE: Thanks to @Pointy and if you want them as numbers, input.match(/\\d+/g).map(Number)
. 注意:感谢@Pointy,如果希望将它们用作数字,请
input.match(/\\d+/g).map(Number)
。
You need to attempt to convert your array values to an integer. 您需要尝试将数组值转换为整数。
To iterate them you can use a for
loop: 要迭代它们,可以使用
for
循环:
for(i=0;i<arrStr.length;i++) {
var result = !isNaN(+arrStr[i]) ? 'number' : 'string';
console.log(result);
}
Here I'm using a unary +
to attempt to convert the value of each array value to a number. 在这里,我使用一元
+
尝试将每个数组值转换为数字。 If this fails, the result will be NaN
. 如果失败,则结果为
NaN
。 I'm then using JavaScript's isNaN()
method to test if this value is NaN
. 然后,我使用JavaScript的
isNaN()
方法测试此值是否为NaN
。 If it isn't, then it's a number, otherwise it's a string. 如果不是,则为数字,否则为字符串。
The result of this using the string you've provided is: 使用您提供的字符串的结果是:
string
string
string
number
string
string
string
string
number
To use this in an if
statement, we can simply: 要在
if
语句中使用它,我们可以简单地:
for(i=0;i<arrStr.length;i++) {
if(isNaN(+arrStr[i])) {
/* Process as a string... */
}
else {
/* Process as a number... */
}
}
To expound on Sniffer's answer... 详细解释Sniffer的答案...
var input = "My name is 123 and my name is 234";
var numberArray = input.match(/\d+/g);
var wordArray = input.match(/[A-Za-z]+/g);
for (var number in numberArray)
{
//do something
}
for (var word in wordArray)
{
//do something
}
While researching, I found out about the Number()
object. 在研究时,我发现了
Number()
对象。 This is generally used to work with manipulation of numbers. 通常用于处理数字。 MDN has a good documentation .
MDN有一个很好的文档。
I found out that Number()
returns NaN
(Not a Number) when not passed a number. 我发现
Number()
未传递数字时返回NaN
(不是数字)。 Since no number returns NaN, It could be a good way to check whether the passed object is string or a number literal. 由于没有数字返回NaN,因此这可能是一种检查传递的对象是字符串还是数字文字的好方法。
So my code would be: 所以我的代码是:
if (Number(arrStr[i]) == NaN){
//string
} else {
//number
}
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