> For the complete documentation index, see [llms.txt](https://docs.adapptio.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.adapptio.com/reference-guide/functions/string.md).

# String

### Contains

*Returns true if a string contains a given substring.*

#### Expression:

**CONTAINS**(*string*: string, *substring*: string)

#### Return:

boolean

#### Example of usage:

```javascript
CONTAINS("The Lord of the Rings", "Harry Potter")

Return value:
false
```

### Starts With

*Returns true if a string starts with a given substring.*

#### Expression:

**STARTS\_WITH**(*string*: string, *substring*: string)

#### Return:

boolean

#### Example of usage:

```javascript
STARTS_WITH("Some sentence.", "Some")

Return value:
true
```

### Concatenate

*Returns a concatenated string.*

#### Expression:

**CONCAT**(*string1*: string, *string2*: string, *string*?: string)

#### Return:

*concatString*: string

#### Example of usage:

```javascript
CONCAT("Dumb and ","Dumber")

Return value:
"Dumb and Dumber"
```

### Lowercase

*Returns a converted string into lowercase.*

#### Expression:

**LOWERCASE**(*value*: string)

#### Return:

*lowercaseString*: string

#### Example of usage:

```javascript
LOWERCASE("MAKING THIS SENTENCE LOWERCASE")

Return value:
"making this sentence lowercase"
```

### Uppercase

*Returns a converted string into lowercase.*

#### Expression:

**UPPERCASE**(*value*: string)

#### Return:

*uppercaseString*: string

#### Example of usage:

```javascript
UPPERCASE("making this sentence uppercase")

Return value:
"MAKING THIS SENTENCE UPPERCASE"
```

### Is Empty

*Returns true if a value is an empty string.*

#### Expression:

**ISEMPTY**(*value*: string)

#### Return:

boolean

#### Example of usage:

```javascript
ISEMPTY("")

Return value:
true
```

### Empty String to Null

*Returns null if a value is empty. Otherwise returns the value as is.*

#### Expression:

**EMPTYNULL**(*value*: string)

#### Return:

null || string

#### Example of usage:

```javascript
EMPTYNULL("")

Return value:
null
```

### Split

*Returns an exact number of split strings to an array using a separator.*

#### Expression:

**SPLIT**(*value*: string, *delimiter*: string, *maximumElements?*: integer)

#### Return:

*splitString*: array

#### Example of usage:

```javascript
SPLIT("My precious | muppet wife", "|")
SPLIT("My precious | muppet wife", "|", 1)

Return value:
["My precious ", " muppet wife"]
["My precious "]
```

### Substring

*Returns a trimmed string bordered by index numbers.*

#### Expression:

**SUBSTRING**(*inputString*: string, start: integer, end: integer)

#### Return:

*trimmedString*: string

#### Example of usage:

```javascript
SUBSTRING("Birds of Paradise", 0, 3)

Return value:
"Bir"
```

### Replace

*Returns a string; a matched one replaces its pattern.*

#### Expression:

**REPLACE**(*inputString*: string, *searchPattern*: string, *replacedPattern*: string)

#### Return:

*replacedString*: string

#### Example of usage:

```javascript
REPLACE("Birds of Paradise", "Birds", "Lions")

Return value:
"Lions of Paradise"
```

### Join Array to a String

*Returns a string of joined array elements with string separators.*

#### Expression:

**JOIN**(*value*: array, *separator*: string)

#### Return:

*joinedString*: string

#### Example of usage:

```javascript
JOIN(["first", "second", "third"]," -> ")

Return value:
"first -> second -> third"
```

### String Lenght

*Returns a number of characters by a given string.*

#### Expression:

**STRLEN**(*value*: string)

#### Return:

*numberOfCharacters*: integer

#### Example of usage:

```javascript
STRLEN("Count my sentence.")

Return value:
18
```