# Sort a variables in structure

1 view (last 30 days)
Gabriele Curcio on 5 May 2022
Edited: Stephen23 on 6 May 2022
I have this kind of variables in a struct:
var_1
var_10
var_11
...
var_19
var_2
var_21
and so on until var_24
Is there a manner to sort them like
var_1
var_2
var_3
var_4
...
var_24
?

Davide Masiello on 5 May 2022
Edited: Davide Masiello on 5 May 2022
See example below
clear,clc
s.var_1 = 1;
s.var_6 = 1;
s.var_3 = 1;
s.var_2 = 1;
s.var_5 = 1;
s.var_4 = 1;
s
s = struct with fields:
var_1: 1 var_6: 1 var_3: 1 var_2: 1 var_5: 1 var_4: 1
orderfields(s)
ans = struct with fields:
var_1: 1 var_2: 1 var_3: 1 var_4: 1 var_5: 1 var_6: 1

Stephen23 on 5 May 2022
Edited: Stephen23 on 6 May 2022
Rather than forcing pseudo-indices into fieldnames, why not use an array with indexing (e.g. a cell array) ?
Here are two ways to sort those fieldnames into alphanumeric order:
S0.var_1 = 101;
S0.var_10 = 110;
S0.var_11 = 111;
S0.var_19 = 119;
S0.var_2 = 102;
S0.var_21 = 121
S0 = struct with fields:
var_1: 101 var_10: 110 var_11: 111 var_19: 119 var_2: 102 var_21: 121
Method 1: REGEXP and SORT (only sorts the numeric part):
[~,X] = sort(str2double(regexp(fieldnames(S0),'\d+\$','match','once')));
S1 = orderfields(S0,X)
S1 = struct with fields:
var_1: 101 var_2: 102 var_10: 110 var_11: 111 var_19: 119 var_21: 121
Method two: NATSORT (must be downloaded first, provides a full alphanumeric sort):
[~,X] = natsort(fieldnames(S0));
S2 = orderfields(S0,X)
S2 = struct with fields:
var_1: 101 var_2: 102 var_10: 110 var_11: 111 var_19: 119 var_21: 121

R2021a

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