I need to parse some numbers from a string, I can get the last number easily but wonder how to get the number mid string reliably. In this case the number 12?

var mystring = 'group 999999999 group-session-info 12 of 50';
var i;
var num; //how to get num "12"
var numOf;
i= mystring.lastIndexOf(" ");
if (i != -1) {
   numOf= mystring.substr(i);
}
alert(numOf); // = 50

Thanks

I need to parse some numbers from a string, I can get the last number easily but wonder how to get the number mid string reliably. In this case the number 12?

var mystring = 'group 999999999 group-session-info 12 of 50';
var i;
var num; //how to get num "12"
var numOf;
i= mystring.lastIndexOf(" ");
if (i != -1) {
   numOf= mystring.substr(i);
}
alert(numOf); // = 50

Thanks

• javascript
• actionscript-3
• apache-flex
• flex3

Share Improve this question Follow edited Nov 23, 2015 at 6:33 ketan 19.4k4242 gold badges6868 silver badges105105 bronze badges asked Nov 17, 2015 at 16:46 Vince LoweVince Lowe 3,63077 gold badges3939 silver badges6363 bronze badges 8

• Are numbers and words always separated by a space? – PM 77-1 Commented Nov 17, 2015 at 16:51
• @PM 77-1 yes seems so – Vince Lowe Commented Nov 17, 2015 at 16:52
• is the question for javascript or actionscript? please remove the relevant tags since both language are not the same at all. All posted answers are javascript is that what you need? – BotMaster Commented Nov 17, 2015 at 21:06
• @BotMaster my implementation will be Actionscript. I added Javascript tag due to the similarities in the languages and basically to draw quick attention to my question. I can easily type the variables etc myself. Do you have a pure actionscript solution? – Vince Lowe Commented Nov 18, 2015 at 7:58
• I figured, that's a bit unfair of you since many of the javascript solution given are not applicable to AS3. Those are different language and even the answer you accepted as is is not patible with as3. I thought there was rules against that practice? – BotMaster Commented Nov 18, 2015 at 12:20

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5 Answers 5

Sorted by: Reset to default 8

Try using regular expression to extract all numbers from the string

var mystring = 'group 999999999 group-session-info 12 of 50';
var r = /\d+/g;
mystring.match(r)

The last sentence will result in an array: [ '999999999', '12', '50' ]

But currently each element in the array is a string. Using parseInt() can turn them into numbers.

Hope this helps.

If the items are always in the format supplied. I would split using the space character.

var mystring = 'group 999999999 group-session-info 12 of 50';
var num = parseInt(mystring.split(' ')[3]); // 4th item which is 12

You'll need to know the context, or know how many numbers there are to find.

With context (for instance, 12 has of after it):

var match = mystring.match(/(\d+) of/);
var num = match && match[1];

num will be the string "12" or null if no number followed by "of" was found.

With knowing how many there are, you just grab all the numbers in the string:

var nums = mystring.match(/\d+/g);

Now nums is an array with the strings "999999999", "12", and "99" in it. (Thanks to epascarello for reminding me that match returns an array with his excellent answer.)

Simple with a regular expression and use map to convert the array of strings to numbers.

var mystring = 'group 999999999 group-session-info 12 of 50';
var nums = mystring.match(/\d+/g).map(Number);

Just to show the correct way but in correct AS3 code and not Javascript for reference:

var mystring:String = 'group 999999999 group-session-info 12 of 50';
var reg:RegExp =  /\d+/g;
var numbers:Array = mystring.match(reg);
trace(Number(numbers[0]))
trace(Number(numbers[1]))
trace(Number(numbers[2]))