Change the position of a field in a structure

I want to add a new field to an already existed structure. But as I try to insert it, it goes at the end position. But I want to change its position to the top

Example:

x=

a: 1

b: 2

c: 3

......

now I insert

x.d=4

it shows

x=

a: 1

b: 2

c: 3

.......

d: 4

but I want it to show

x=

d: 4

a: 1

b: 2

c: 3

......

[Stephen23]

The simplest solution is to add the field and then use this:

https://www.mathworks.com/help/matlab/ref/orderfields.html

You could automate the entire process with the help of:

https://www.mathworks.com/help/matlab/ref/fieldnames.html

[Mehmed Saad]

orderfields(x,{'d','a','b','c'})

[Abdulah Al Mubin]

I can’t write 'a','b','c' manually, I have more than hundred fields

[Stephen23]

"I can’t write 'a','b','c' manually, I have more than hundred fields"

Did you try fieldnames, as I suggested?

[Abdulah Al Mubin]

It worked, but I was hoping for a built-in function to reduce lines

Answer 1

[Walter Roberson]

Use struct2cell() on the old structure, and fieldnames() . Then insert a new cell of values for the new field at the top of the cell of data, and insert the new field name at the top of the list. Now use cell2struct() to create the new structure in the order you want.

This is the only way to control the order of fields when you insert a new field into a structure.

I would suggest to you, however, that it is easier to allow the new field to be put at the end of the struct fields, and then use orderfields() to change the field orders.