# string Functions Use `string` functions in rules to manipulate text strings in asset JSON at runtime. For instance, a string function can replace all occurrences of one string with another or convert strings from uppercase to lowercase. If a user enters a dashboard title in the wizard using all lowercase letters, the string function changes the text to sentence case at runtime. ## toUpperCase Parameters: Object Returns: Object Recursive: Supported Description: Converts all characters in an object to uppercase. The object can be a single string or a JSON object with multiple strings ## Example This JSON ```nolang    "objecttest" : {        "obj" : {            "greeting1" : "hello world",            "greeting2" : "salut world",            "greeting3" : "hallo world"        },        "list" : ["hello world", "salut world", "hallo world"]    }, ``` And the rule: ```nolang {    "action": "set",    "description": "Convert all strings to upper case",    "path": "$.objecttest",    "value" : "${string:toUpperCase(Rules.CurrentNode)}" } ``` Returns: ```nolang "objecttest" : {        "obj" : {            "greeting1" : "HELLO WORLD",            "greeting2" : "SALUT WORLD",            "greeting3" : "HALLO WORLD"        },        "list" : ["HELLO WORLD", "SALUT WORLD", "HALLO WORLD"]    }, ``` ## toLowerCase Parameters: Object Returns: Object Recursive: Supported Description: Converts all characters in a string to lowercase. ## replace Parameters: Object `obj`, String `oldStr`, String `newStr` Returns: Object Recursive: Supported Description: Returns a new object with all occurrences of `oldStr` replaced with `newStr`. ## replaceAll Parameters: Object `obj`, String `regex`, String `newStr` Returns: Object Recursive: Supported Description: Replaces all substrings of this string that match the given [regular expression](https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#sum). ## replaceFirst Parameters: Object `obj`, String `regex`, String `newStr` Returns: Object Recursive: Supported Description: Replaces the first substring of this string that matches the given [regular expression](https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#sum). ## split Parameters: Object `obj`, String `regex` Returns: Object Recursive: Supported Description: Parses a string and splits it into an array defined by the specified delimiter. For example: ```nolang ${string:split('one:two:three', ':')} ``` Results in array of strings: ```nolang ['one','two','three'] ``` If more complex regular expression matching is required, use `match` (next). ## match Parameters: Object `obj`, String `regex` Returns: Object Recursive: Supported **Description:** Performs complex regular expression matching and returns an array of matching results. For example, to capture items surrounded by square single quote and square brackets: ```nolang ${string:match('['foo']['bar']['baz']', '\\\\[\\'(.*?)\\'\\\\]') ``` Returns the following array: ```nolang foo
 bar baz ``` ## join Parameters: Object `obj`, String delimiter Returns: Object Recursive: Supported Description: Creates a string from an array of strings and separates each item by the specified delimiter. ```nolang ${string:join(, )} ```