---
url: >-
  /statelake/scripting-reference/functions-and-procedures/string-functions/stringreplacefirst.md
---

# StringReplaceFirst

**StringReplaceFirst** has similar functionality to **StringReplaceAll**, except that **StringReplaceFirst** replaces the first occurrence only of **OldPattern** with **NewPattern** in **S** string.

**OldPattern** can be one or more characters.

**NewPattern** can be one or more characters, or it can be blank, which effectively removes the first occurrence of **OldPattern**.

**StringReplaceFirst** is not sensitive to case - **A** is read as the same as **a**.

Also review [StringReplaceAll](/statelake/scripting-reference/functions-and-procedures/string-functions/stringreplaceall).

**Declaration**: Function StringReplaceFirst( const S, OldPattern, NewPattern : string) : string;

A few examples.

```pascal
procedure OnMapEvent(var Value:Variant);
var
  Str1, Str2, Str3, Str4 : string;
begin
  Str1 := '[Topic]Rhubarb [Topic]Lizards [Topic]Yurts [Topic]Permaculture'

 //Returns 'abc|def#g'
  Str2 := StringReplaceFirst('abc#def#g','#','|');
  LogInfo(Str2);

 //Returns '[Follow The Topics - Topic]Rhubarb [Topic]Lizards [Topic]Yurts [Topic]Permaculture'
  Str3 := StringReplaceFirst(Str1,'topic','Follow The Topics - Topic');
  LogInfo(Str3);

 //Returns '12345678901234567890'
  Str4 := StringReplaceFirst('012345678901234567890','0','');
  LogInfo(Str4);

end;
```