# jBC String Operations

A substring can be extracted with the notation:

`substring = stringvalue[x{,y}]`

A substring can be assigned with the notation:

`stringvalue[x,y] = "newstring"`

[Note that y is not optional when used in this context]

Where:

• x is the starting position
• y is specifies the substring length

If x = 0 then 1 is assumed.
If x > 0 then the starting position is x.
If x < 0 then the starting position is taken x characters from the end of the string.
If x > LEN(stringvalue) then '' is returned regardless of the value of y.

If y is not specified then all characters starting with x up to the end of the string are returned.
If y = 0 then '' is returned.
If y > 0 then y characters are extracted starting at position x. If y is greater than the remaining characters in the string then all characters up to the end of the string are returned.
If y < 0 then the pointer is positioned y characters from the end of the string (i.e. LEN(stringvalue) - y + 1), and the substring is taken up to that position.

## Examples

Given the strings:

```s = "Anyone who needs a will just isn't spending their money properly."
t = " all of "```

s[1,999] returns s
s[1,-1] returns s
s[0,-1] returns s
s[1,3] returns "Any"
s[4,3] returns "one"
s[-15,-10] returns "money"
s[-15,5] returns "money"
s[999,10] returns ''
s[1,0] returns ''

s[-22,1] = t returns "Anyone who needs a will just isn't spending all of their money properly." to s.

## Note:

Negative substring operations are not available in all emulations. Consult your legacy manual.]