ios - Update UILabel based on selected table view rows -

i have table view , text field. whatever person selects in table view appear in textfield.

example: in table view choices "one" "two" "three"

if select "one", checkmark appears on tableview , "one" appear in text field well.

i know how add strings using stringbyappendingstring, when select "two", , "one" still selected, label appear "onetwo"

now question: if deselect "one" choice (or other choice matter), how can delete portion of concatenated string?

example: if selected in order "threeonetwo" , wanted deselect "one", label appear "threetwo".

thank you.

update: have done far , stuck.

first: created mutable array:

nsmutablearray *tobefilledtabledata;

then allocated it:

tobefilledtabledata = [[nsmutablearray alloc] init];

then, if user selects option table view, add 1 object:

[tobefilledtabledata addobject:@"one"];

i changed mind on having textfield appear "threeonetwo", i'd add semicolon in between instead want appearance "three;one;two". created string add semicolon @ end:

nsstring *combinedforces

combinedforces = [tobefilledtabledata componentsjoinedbystring:@";"]; (^ not displaying semicolon instead i'll add semicolon addobject [unless there way it])

then displayed object in text field:

textfield.text = combinedforces;

so of right now, 1. list not populating click more options , 2. inserting semicolon in between each choice becoming puzzle. i'd appreciate =)

instead of deleting portion of string, maintain array or set selected items.

in didselectrowatindex path method add selected string array (or remove it) , call updatelabel method, creates string contents of array or set.

thus, string recreated every time change happens.

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if want know order of selection, use nsmutableorderedset, if don't need know order, can use nsmutableset.