String Functions
String Functions
Studio provides a set of functions for working with strings in expressions.
| Function | Arguments Description |
|---|---|
substring() |
Extracts a specified substring from a given string. |
startsWith() |
Determines whether a string begins with specific characters. |
endsWith() |
Determines whether a string ends with specific characters. |
stringLength() |
Determines the number of characters in the specified string. |
indexOf() |
Determines the index of the first occurrence of a substring. |
lastIndexOf() |
Determines the index of the last occurrence of the specified value, searching backward. |
toUpperCase() |
Convert all characters in a string to upper case. |
toLowerCase() |
Convert all characters in a string to lower case. |
replace() |
Replaces substrings within a string. |
contains() |
Determines whether one string may be found within another string. |
charAt() |
Get a new string containing the single character unit located at the specified offset. |
padStart() |
Pads the front of the input string with another string until the resulting string reaches the given length. |
padEnd() |
Pads the end of the input string with another string until the resulting string reaches the given length. |
trim() |
Removes whitespace from both ends of a string. |
trimStart() |
Removes whitespace from the start of a string. |
trimEnd() |
Removes whitespace from the end of a string. |
matches() |
Returns true for strings that match the provided regex. |
firstMatch() |
Returns the first string that matches given the provided regex. |
Remarks
- All indices into strings are zero-based, meaning that the first character has index
0, not1.
API Reference
substring
Extracts a specified substring from a given string.
TypeScript
substring(string: string, startIndex: integer, endIndex?: integer): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The string to extract a substring from. |
startIndex |
int |
The index of the first character to be included. |
endIndex |
int |
The index of the first character to be excluded. If omitted, all characters to the end of the string are included. |
Returns
Returns a new string containing the specified part of the given string.
Notes
- If startIndex is equal to
endIndex,substring()returns an empty string. - If
startIndexis greater thanendIndex, the effect ofsubstring()is as if the two arguments were swapped.
startsWith
Determines whether a string begins with the characters of another string.
TypeScript
startsWith(string: string, searchString: string, startIndex: integer): boolean
| Parameter | Type | Description |
|---|---|---|
string |
string |
The string to extract a substring from. |
searchString |
string |
The substring to look for. |
startIndex |
int |
The index of the first character to be included. |
Returns
Returns true or false as appropriate.
Notes
This method is case-sensitive.
endsWith
Determines whether a string ends with the characters of a specified string.
TypeScript
endsWith(string: string, searchString: string, fromIndex?: integer): boolean
| Parameter | Type | Description |
|---|---|---|
string |
string |
The string to extract a substring from. |
searchString |
string |
The substring to check for. |
fromIndex |
int |
The index of the last character to be included. Defaults to the end of the string. |
Returns
Returns true or false as appropriate.
Notes
This method is case-sensitive.
stringLength
Determines the number of characters in the specified string.
TypeScript
stringLength(string: string): integer
| Parameter | Type | Description |
|---|---|---|
string |
string |
The string to check for length. |
Returns
Returns the number of characters in the given string.
indexOf
Determines the index of the first occurrence of a substring.
TypeScript
indexOf(string: string, substring: string, startIndex?: integer): integer
| Parameter | Type | Description |
|---|---|---|
string |
string |
The string to find a substring in. |
substring |
string |
The string to check for. |
fromIndex |
int |
The index to search backward from. Defaults to end of string. |
Returns
Returns the index of the first occurrence of substring; -1 if not found.
lastIndexOf
Determines the index of the last occurrence of the specified value, searching backward.
TypeScript
lastIndexOf(string: string, searchString: string, fromIndex?: integer): integer
Returns
Returns the index of the last occurrence of substring; -1 if not found.
toUpperCase
Convert all characters in a string to upper case.
TypeScript
toUpperCase(string: string): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string to convert to upper case. |
Returns
Returns a new string with all lower case characters replaced with upper case characters.
Notes
The specifics of case conversion may depend on the current locale, determined by the browser and the operating system.
toLowerCase
Convert all characters in a string to lower case.
TypeScript
toLowerCase(string: string): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string to convert to lower case. |
Returns
Returns a new string with all upper case characters replaced with lower case characters.
Notes
The specifics of case conversion may depend on the current locale, determined by the browser and the operating system.
replace
Replaces substrings within a string.
TypeScript
replace(string: string, searchString: string, newSubstring: string): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string containing a substring to be replaced. |
searchString |
string |
The substring to be replaced. |
newSubstring |
string |
The replacement string. |
Returns
Returns a string with the replaced substring, or an unaltered string if no searchString was found.
contains
Determines whether one string may be found within another string.
TypeScript
contains(string: string, searchString: string): boolean
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string to evaluate for a substring. |
searchString |
string |
The substring to search for. |
Returns
Returns true if the searchString is found inside the supplied string, otherwise false.
charAt
Get a new string consisting of the single character unit located at a specified offset.
TypeScript
charAt(string: string, index: integer): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string. |
index |
int |
The index of the character. |
Returns
Returns a string containing the character at index at the specified index. If index is out of range, an empty string is returned.
padStart
Pads the front of the input string with another string until the resulting string reaches the given length.
TypeScript
padStart(string: string, targetLength: integer, padString?: string): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string. |
targetLength |
int |
The minimum length of the returned string. |
padString |
string |
Optional. Applied (multiple times, if needed) from the start of the current string. Defaults to ' ' (Unicode Character U+0020 'SPACE'). |
Returns
Returns a string that has at least targetLength characters.
padEnd
Pads the end of the input string with another string until the resulting string reaches the given length.
TypeScript
padEnd(string: string, targetLength: integer, padString?: string): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string. |
targetLength |
int |
The minimum length of the returned string. |
padString |
string |
Optional. Applied (multiple times, if needed) from the end of the current string. Defaults to ' ' (Unicode Character U+0020 'SPACE'). |
Returns
Returns a string that has at least targetLength characters.
trim
Removes whitespace from both ends of a string.
TypeScript
trim(string: string): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string. |
Returns
Returns a string without leading and trailing whitespace.
trimStart
Removes whitespace from the start of a string.
TypeScript
trimStart(string: string): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string. |
Returns
Returns a string with leading whitespace stripped.
trimEnd
Removes whitespace from the end of a string.
TypeScript
trimEnd(string: string): string
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string. |
Returns
Returns a string with trailing whitespace stripped.
matches
Determines whether a string matches the provided regex.
TypeScript
matches(string: string, regex: string): boolean
| Parameter | Type | Description |
|---|---|---|
string |
string |
The input string. |
regex |
string |
The regex argument to use in a search. |
Returns
Returns true if a string matches the provided regex, false otherwise.
firstMatch
Finds the first string that matches the provided regex.
TypeScript
firstMatch(string: string, regex: string): string
Returns
Returns the first string that matches the provided regex.