Short Answer
You can use String.Insert.
String.Insert
public string Insert(
int startIndex,
string value
)
startIndex
Type: System.Int32
The zero-based index position of the insertion.
value
Type: System.String
The string to insert.
Explanation
This Method inserts a string into another string at the specified index position. The first parameter, startIndex
is the zero-based index position of the insertion, and you want to insert it at the index position of 3
, and you want the first parameter to be 3
. The second parameter is the string to insert, and you want to insert -
, so set the second parameter to a -
.
Code:
string idnumber = "0002232";
string displayednumber = idnumber.Insert(3, "-");
Result:
displayednumber = "000-2232"
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solved Insert A Character After 7 Characters (C#) [closed]