How Would I "Shift" the values in an Array?

[Scoptile]

What I would like to do is move all the values in an array from a certain point over one. Like this:

array[1] = "value1"
array[2] = "value2"
array[3] = "value3"

becomes:

array[1] = "value1"
array[2] = ""
array[3] = "value2"
array[4] = "value3"

if you "shift" it at the second value
sorry if this is confusing.

 

[Paolo Mazzon]

I think what you're looking for is ds_list_insert which does exactly that. Lists are fairly straightforward, they're basically just arrays with some very useful functions built in. As a quick side note, it probably doesn't matter to what you're doing, but I'll mention it anyways, if you have a ton of things in the list, and then put something at the start of it, it will be fairly heavy since it then has to loop through the whole list and displace everything.

 

[Scoptile]

I think what you're looking for is ds_list_insert which does exactly that. Lists are fairly straightforward, they're basically just arrays with some very useful functions built in. As a quick side note, it probably doesn't matter to what you're doing, but I'll mention it anyways, if you have a ton of things in the list, and then put something at the start of it, it will be fairly heavy since it then has to loop through the whole list and displace everything.

im trying that out now. do you know of a way to overwrite an existing value in the ds list?

 

[Aura]

http://docs.yoyogames.com/source/da...data structures/ds lists/ds_list_replace.html

 

[Scoptile]

thanks

 

[Paolo Mazzon]

@Scoptile, yes, you can still use array notation (myarray[x]) with lists, just with lists make sure you put a | before the number. (So arr[4] would be arr[|4] if it was a list)

 

[Aura]

For the sake of completeness, | is called the list accessor. You can read everything about accessors here:

http://docs.yoyogames.com/source/dadiospice/002_reference/001_gml language overview/accessors.html

 

[wamingo]

ds_list is all but certainly the right answer, but here's a way to shift forward and insert into a 1d array:

// forward shift from index 2
var shiftfrom = 2;
for (var i=array_length_1d(a); i>shiftfrom; i--){
  a[i]=a[i-1];
}
// insert
a[shiftfrom] = 'newdata';