如何使用javascript获取电话号码中的特定号码

Question

I would like to get the following number after the first "7" in a phone number. Let's say "077777777" its "7" and "0788787878" its "8" and "0727923743" is "2" etc how can i do this in javascript i was thinking of something like this

 var phone = 0784848236.substring(0784848236.indexOf("7")); 

but its far different.

Answer 1

You could use a regular expression:

 var match = '0784848236'.match(/7(.)/); match = match && match[1]; console.log(match); 

NB: This will result in null when there is no match.

Note that it is important to have your phone number in string format. If you use a number data type, and have it converted to string on the fly, you'll loose prepadded zeroes. See how looking for a zero fails in this case:

 var phone = 0784848236; var match = String(phone).match(/0(.)/); match = match && match[1]; console.log(match); // null !!! The zero is lost. 

Answer 2

Your code is close, but has two issues:

1. 0784848236 is an int, not a string, so you cannot call substring() or indexOf() on it. You should instead use "0784848236" (in quotes).
2. substring() gives you the entire string after the specified index, but you only want the first character of that substring. So you don't actually need to use substring() here at all. Instead, you can just use direct access (index into).

Instead, try something like this:

var phone = "0784848236"["0784848236".indexOf("7") + 1];

Answer 3

In order to use the substring method, you need to pass in a string.

You also need to provide a start and end index. Here is the reference for the method: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/substring str.substring(indexStart[, indexEnd])

If I was to change your question by declaring a string from the phone number then I could use substring on the string. Like this:

var pn = '0784848236';
var n = pn.substring(pn.indexOf("7") + 1, pn.indexOf("7") + 2);

Now the result will be the next number following the '7'

Answer 4

to get the following number after the first "7" in a phone number

Here are two approaches:

String.prototype.substr() and String.prototype.indexOf() functions approach:

 var phone = 0784848236, i, strPhone = String(phone), // string representation of phone number nextDigit = ((i = strPhone.indexOf("7")) !== -1)? strPhone.substr(i + 1, 1) : null; console.log(nextDigit); 

---

String.prototype.split() and Array.prototype.indexOf() functions approach:

 var phone = 0784848236, arr = (''+0784848236).split(''), i, nextDigit = ((i = arr.indexOf("7")) !== -1)? arr[i+1] : null; console.log(nextDigit); 

Answer 5

Here's what's working for me:

var num="0784848236";
var numberSeven = num.indexOf("7");

var yourNumber = num.substring((numberSeven + 1), (numberSeven + 2));