### string() function example

Source: https://docs.surveycto.com/02-designing-forms/01-core-concepts/09.expressions.html

Converts a field to a string. Example returns true.

```expression
`string(34.8) = '34.8'`
```

--------------------------------

### concat() function example

Source: https://docs.surveycto.com/02-designing-forms/01-core-concepts/09.expressions.html

Concatenates fields and/or strings. Example returns a full name.

```expression
`concat(${firstname}, ' ', ${lastname})`
```

--------------------------------

### phone-call-log() output example

Source: https://docs.surveycto.com/02-designing-forms/01-core-concepts/09.expressions.html

Example output of phone-call-log() in a calculate field, showing call events with timestamps.

```plaintext
Form started||0
Call started|5555555555|12
Form exited (call in progress)|5555555555|25
Form resumed (call in progress)|5555555555|26
Call ended|5555555555|45
Form exited||77
```

--------------------------------

### linebreak() function example

Source: https://docs.surveycto.com/02-designing-forms/01-core-concepts/09.expressions.html

Returns a linebreak character. Example returns a list of three field values with linebreaks between them.

```expression
`concat(${field1}, linebreak(), ${field2}, linebreak(), ${field3})`
```

--------------------------------

### upper() function example

Source: https://docs.surveycto.com/02-designing-forms/01-core-concepts/09.expressions.html

Converts a string to all uppercase characters. Example returns "STREET NAME".

```expression
`upper('Street Name')`
```

--------------------------------

### substr() function example

Source: https://docs.surveycto.com/02-designing-forms/01-core-concepts/09.expressions.html

Returns a substring starting at startindex and ending just before endindex. Indexes start at 0. Example returns the first three digits of a phone number.

```expression
`substr(${phone}, 0, 3)`
```