如何在javascript中的n位数之后拆分数字？

Question

I have a number 2802 which is stored as a string in the backend. I want to split this number into 2 parts as 28 and 02 which should be shown as date 28/02? How can I do it with '/' in between them?

Answer 1

Try this : you can use substring as shown below. substring used for getting string between start index and end index. In your case, get string from 0 to 1 and then 2 to 3.

 var str = "2802"; str = str.substring(0,2) + "/" + str.substring(2,4); alert(str); 

More information on Substring

Answer 2

Solution with regex

 var res = "2802".match(/\\d{2}/g).join('/'); document.write(res); 

Answer 3

Are you asking about simple string manipulation?

var str = "1234";
var res = str.substr(0, 2)+"/"+str.substr(2,4);

Answer 4

You can do this:

 var str = "2802"; str = str.split('').map(function(el, i){ if(i == 2){ el = '/'+el} return el; }); document.querySelector('pre').innerHTML = str.join(''); 

 <pre></pre> 

With regular expression:

 var str = "2802"; str = str.replace(/(.{1,2}$)/gi, '/$1'); document.querySelector('pre').innerHTML = str; 

 <pre></pre> 

Answer 5

var str = "2802";
var output = [str.slice(0, 2), str.slice(2)].join('/');

Answer 6

In this context conside 2802, 28 is date and 02 is month

Here 112 , 028 what is date and month ?

Answer 7

A more generic solution could be

var num = 2802;
var output = String(num).match(new RegExp('.{1,2}', 'g')).join("/");

replace 2 with which ever number to split the number after n digits.

var n = 2;
var output = String(num).match(new RegExp('.{1,'+n+'}', 'g'));

Answer 8

var db_date = '112';
var date_str = '';
if(db_date.slice(0,1)==0){
    var date_val = db_date.slice(0,2);
    var month_val = db_date.slice(2,3);

    if(month_val<=9){
        month_val = '0'+month_val;
    }
}else{
    var date_val = db_date.slice(0,1);
    date_val = parseInt(date_val);
    if(date_val<=9){
        date_val = date_val.toString();
        date_val = '0'+date_val;
    }
    var month_val = db_date.slice(1,3);
}
alert(date_val+'/'+month_val);