Asp Forum - Remove leading zeros in index of array

JT

3/23/2015 11:58:00 AM

I store integers in the indexes of an array, is there a prefared or easy way to remove all leading indexes containing zeros?

To use splice i have to loop thru the array?

bin=[0,0,0,1,0,1,0,1]

16 Answers

JT

3/23/2015 5:03:00 PM

Den måndag 23 mars 2015 kl. 12:58:08 UTC+1 skrev jonas.t...@gmail.com:
> I store integers in the indexes of an array, is there a prefared or easy way to remove all leading indexes containing zeros?
>
> To use splice i have to loop thru the array?
>
> bin=[0,0,0,1,0,1,0,1]

This is what i've come up with.

while (result[length]==0) {result.splice(length, 1);length+=-1;}

Scott Sauyet

3/23/2015 5:33:00 PM

jonas.thornvall@gmail.com wrote:
> jonas.thornvall@gmail.com wrote:
>> I store integers in the indexes of an array, is there a prefared
>> or easy way to remove all leading indexes containing zeros?
>> [ ... ]
> This is what i've come up with.
>
> while (result[length]==0) {result.splice(length, 1);length+=-1;}

One possibility:

var removeLeadingZeros = function(list) {
var firstNonZero = 0;
list.every(function(item, index) {
if (item !== 0) {
firstNonZero = index;
return false;
}
return true;
});
return list.slice(firstNonZero);
};

This depends on `Array.prototype.every` which is not available in JScript
before Chakra (i.e. before IE9), and would have to be polyfilled if you
wanted to use it in that environment.

While it's not a beautiful solution, it certainly seems better than
continually `splice`ing out values. Note that this does *not* modify your
original list but returns a copy of it. To my mind this is an advantage;
but if you prefer, you could always replace that last line with a single
`splice` call.

-- Scott

Tim Streater

3/23/2015 6:37:00 PM

In article <27052983-4f87-4ee8-9778-8337a84e359f@googlegroups.com>,
<jonas.thornvall@gmail.com> wrote:

>Den mÃ¥ndag 23 mars 2015 kl. 12:58:08 UTC+1 skrev jonas.t...@gmail.com:
>> I store integers in the indexes of an array, is there a prefared or easy way
>> to remove all leading indexes containing zeros?
>>
>> To use splice i have to loop thru the array?
>>
>> bin=[0,0,0,1,0,1,0,1]
>
>This is what i've come up with.
>
>while (result[length]==0) {result.splice(length, 1);length+=-1;}

Or possibly:

length -= 1;

--
"People don't buy Microsoft for quality, they buy it for compatibility
with what Bob in accounting bought last year. Trace it back - they buy
Microsoft because the IBM Selectric didn't suck much" - P Seebach, afc

Evertjan.

3/23/2015 7:43:00 PM

jonas.thornvall@gmail.com wrote on 23 mrt 2015 in comp.lang.javascript:

> Den måndag 23 mars 2015 kl. 12:58:08 UTC+1 skrev jonas.t...@gmail.com:
>> I store integers in the indexes of an array, is there a prefared or easy
> way to remove all leading indexes containing zeros?
>>
>> To use splice i have to loop thru the array?
>>
>> bin=[0,0,0,1,0,1,0,1]
>
> This is what i've come up with.
>
> while (result[length]==0) {result.splice(length, 1);length+=-1;}

var a = [0,0,0,3,0,7,0,1];

while (a[0]==0)
a.splice(0, 1);

alert(a);

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

JT

3/23/2015 7:58:00 PM

Den måndag 23 mars 2015 kl. 20:42:54 UTC+1 skrev Evertjan.:
> jonas.thornvall@gmail.com wrote on 23 mrt 2015 in comp.lang.javascript:
>
> > Den måndag 23 mars 2015 kl. 12:58:08 UTC+1 skrev jonas.t...@gmail.com:
> >> I store integers in the indexes of an array, is there a prefared or easy
> > way to remove all leading indexes containing zeros?
> >>
> >> To use splice i have to loop thru the array?
> >>
> >> bin=[0,0,0,1,0,1,0,1]
> >
> > This is what i've come up with.
> >
> > while (result[length]==0) {result.splice(length, 1);length+=-1;}
>
> var a = [0,0,0,3,0,7,0,1];
>
> while (a[0]==0)
> a.splice(0, 1);
>
> alert(a);
>
> --
> Evertjan.
> The Netherlands.
> (Please change the x'es to dots in my emailaddress)

Sorry Evertjan i probably wrote in the values wrong way out of head, the zeros will range from highest index.

But while
while (a[length]==0) {a.splice(length, 1);length--;}
alert(a);

while (result[length]==0) {result.splice(length, 1);length+=-1;}
Basicly same.

Evertjan.

3/23/2015 8:12:00 PM

jonas.thornvall@gmail.com wrote on 23 mrt 2015 in comp.lang.javascript:

> Sorry Evertjan i probably wrote in the values wrong way out of head, the
> zeros will range from highest index.
>
> But while
> while (a[length]==0) {a.splice(length, 1);length--;}
> alert(a);
>
> while (result[length]==0) {result.splice(length, 1);length+=-1;}
> Basicly same.

Not the same, you sh/could use pop() here:

=============================
var a = [3,0,7,0,1,0,0,0]

while (a[a.length-1]==0) a.pop();

alert(a);
=============================

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

JT

3/23/2015 8:16:00 PM

Den måndag 23 mars 2015 kl. 21:12:28 UTC+1 skrev Evertjan.:
> jonas.thornvall@gmail.com wrote on 23 mrt 2015 in comp.lang.javascript:
>
> > Sorry Evertjan i probably wrote in the values wrong way out of head, the
> > zeros will range from highest index.
> >
> > But while
> > while (a[length]==0) {a.splice(length, 1);length--;}
> > alert(a);
> >
> > while (result[length]==0) {result.splice(length, 1);length+=-1;}
> > Basicly same.
>
> Not the same, you sh/could use pop() here:
>
> =============================
> var a = [3,0,7,0,1,0,0,0]
>
> while (a[a.length-1]==0) a.pop();
>
> alert(a);
> =============================
>
> --
> Evertjan.
> The Netherlands.
> (Please change the x'es to dots in my emailaddress)

Thank you, i will try.

Evertjan.

3/23/2015 8:37:00 PM

jonas.thornvall@gmail.com wrote on 23 mrt 2015 in comp.lang.javascript:

>> ========================
>> var a = [3,0,7,0,1,0,0,0]
>>
>> while (a[a.length-1]==0) a.pop();
>>
>> alert(a);
>> ========================
>>
> Thank you, i will try.

Since pop() returns what is popped,
you could try this less efficient,
but perhaps also enjoyable way:

====================
var a = [3,0,7,0,1,0,0,0];
var b = a.slice(); // copy array a to b

while (b.pop() == 0) {a.pop()};

alert(a);
====================

and if you want to see what is happening,
insert an alert():

while (b.pop() == 0) {alert(a.pop())};

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

Evertjan.

3/23/2015 8:50:00 PM

"Evertjan." <exxjxw.hannivoort@inter.nl.net> wrote on 23 mrt 2015 in
comp.lang.javascript:

> jonas.thornvall@gmail.com wrote on 23 mrt 2015 in comp.lang.javascript:
>
>>> ========================
>>> var a = [3,0,7,0,1,0,0,0]
>>>
>>> while (a[a.length-1]==0) a.pop();
>>>
>>> alert(a);
>>> ========================
>>>
>> Thank you, i will try.
>
> Since pop() returns what is popped,
> you could try this less efficient,
> but perhaps also enjoyable way:
>
> ====================
> var a = [3,0,7,0,1,0,0,0];
> var b = a.slice(); // copy array a to b
>
> while (b.pop() == 0) {a.pop()};
>
> alert(a);
> ====================

Or push the popped nonzero element back:

=================
var a = [3,0,7,0,1,0,0,0], temp;

while ( (temp = a.pop()) == 0) {};

a.push(temp);

alert(a);
=================

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

Evertjan.

3/23/2015 8:58:00 PM

"Evertjan." <exxjxw.hannivoort@inter.nl.net> wrote on 23 mrt 2015 in
comp.lang.javascript:

> "Evertjan." <exxjxw.hannivoort@inter.nl.net> wrote on 23 mrt 2015 in
> comp.lang.javascript:
>
>> jonas.thornvall@gmail.com wrote on 23 mrt 2015 in comp.lang.javascript:
>>
>>>> ========================
>>>> var a = [3,0,7,0,1,0,0,0]
>>>>
>>>> while (a[a.length-1]==0) a.pop();
>>>>
>>>> alert(a);
>>>> ========================
>>>>
>>> Thank you, i will try.
>>
>> Since pop() returns what is popped,
>> you could try this less efficient,
>> but perhaps also enjoyable way:
>>
>> ====================
>> var a = [3,0,7,0,1,0,0,0];
>> var b = a.slice(); // copy array a to b
>>
>> while (b.pop() == 0) {a.pop()};
>>
>> alert(a);
>> ====================
>
> Or push the popped nonzero element back:
>
> =================
> var a = [3,0,7,0,1,0,0,0], temp;
>
> while ( (temp = a.pop()) == 0) {};
>
> a.push(temp);
>
> alert(a);
> =================

Or you could use regex,
if the values are single digits:

===============
var a = [1,0,4,0,1,0,0,0];

a = a.join('').replace(/0*$/,'').split('');

alert(a);
===============

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

comp.lang.javascript

Remove leading zeros in index of array

JT

JT

Scott Sauyet

Tim Streater

Evertjan.

JT

Evertjan.

JT

Evertjan.

Evertjan.

Evertjan.

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