# _CP_index

_CP_index is equivalent to the `*result* = index(*string1*, *string2*, *expression*)` BASIC
statement.

## Syntax

```
int _CP_index(int* result, CPSTR* string1, CPSTR* string2, int expression)
```

## Description

This function returns -1 if
an error occurs. The error code is contained in _CP_errno.

## Example(s)

```
/* Prints "2". */

CPSTR * s = _CP_mkstr("bbc");
CPSTR * t = _CP_mkstr("b");
int i;

_CP_index(&i,s,t,2);
_CP_unix_env();
printf("%d\n", i);
```

## See also

- [C functions overview](https://d3codex.com/cfunctions/c-functions-overview/)

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Source: https://d3codex.com/cfunctions/cp-index/ - part of the D3Codex reference.