String
length number
at(index) function
Return the character (or surrogate pair) at the specified index, with support for negative indices (counting from the end). If the index is out of range, returns undefined.
index: The position of the character to return (can be negative).
Returns: A string of length 1 representing the character, or undefined if out of range.
charCodeAt(index) function
Return a number indicating the UTF-16 code unit value at the given index. If the index is out of range, returns NaN.
index: An integer between 0 and string length - 1.
Returns: An integer in the range [0, 65535] or NaN if out of range.
charAt(index) function
Return a string consisting of the single UTF-16 code unit at the given index. If the index is out of range, returns an empty string.
index: The zero-based index of the desired character.
Returns: The single-character string at the specified index, or '' if out of range.
concat(stringN) function
Concatenate the provided string arguments to the current string and return a new string.
stringN: One or more strings to concatenate.
Returns: A new string formed by joining the caller with the provided arguments.
codePointAt(position) function
Return a non-negative integer that is the Unicode code point value at the given position. Supports code points above 0xFFFF. Returns undefined if index is out of range.
position: The index in the string (can be surrogate pairs).
Returns: The code point value, or undefined if out of range.
isWellFormed() function
Return a boolean indicating whether the string is valid Unicode. If it contains unpaired surrogate code points, return false.
Returns: True if the string is well-formed UTF-16, otherwise false.
toWellFormed() function
Return a new string in which any unpaired surrogate code points have been replaced by the Unicode replacement character U+FFFD.
Returns: A well-formed UTF-16 version of the string.
indexOf(searchValue, fromIndex) function
Return the zero-based index of the first occurrence of 'searchValue' in the string, starting at 'fromIndex'. If not found, return -1.
searchValue: The substring to search for.
fromIndex: The index at which to begin searching (default 0).
Returns: The index of the first match, or -1 if not found.
lastIndexOf(searchValue, fromIndex) function
Return the zero-based index of the last occurrence of 'searchValue' in the string, searching backwards from 'fromIndex'. If not found, return -1.
searchValue: The substring to search for.
fromIndex: The index at which to begin the backward search (defaults to string length - 1).
Returns: The index of the last match, or -1 if not found.
includes(searchString, position) function
Return a boolean indicating whether 'searchString' appears within this string. An optional position can be provided to start searching.
searchString: The substring to search for.
position: The position from which to begin searching (default 0).
Returns: True if the substring is found, otherwise false.
endsWith(searchString, length) function
Return a boolean indicating whether the string ends with 'searchString'. An optional 'length' can be provided to treat the string as if it were only that long.
searchString: The substring to search for at the end.
length: An optional length to truncate the string before testing.
Returns: True if the string ends with 'searchString', otherwise false.
startsWith(searchString, position) function
Return a boolean indicating whether the string begins with 'searchString'. An optional position can be provided to start checking at that index.
searchString: The substring to search for at the start.
position: The index in the string to start searching (default 0).
Returns: True if the string starts with 'searchString', otherwise false.
match(regexp) function
Use a regular expression to match the string. If 'regexp' is not a RegExp, it is converted to one. Return an array of matches or null if none found.
regexp: The pattern to match (RegExp or string).
Returns: An array of matches or null.
matchAll(regexp) function
Return an iterator of all RegExp match objects found within the string. If 'regexp' is not a global or sticky RegExp, a TypeError is thrown.
regexp: The global/sticky RegExp to match over this string.
Returns: An iterator of match arrays.
search(regexp) function
Use a regular expression to search for a match within the string. Return the index of the first match, or -1 if no match is found.
regexp: A RegExp or string. If a string, it is converted to RegExp.
Returns: The index of the first match, or -1 if not found.
split(separator, limit) function
Split the string into an array of substrings using 'separator' (RegExp or string). An optional 'limit' can be provided to limit the number of splits.
separator: A string or RegExp used to divide the string.
limit: Maximum number of splits to include in the result array.
Returns: An array of the split substrings.
substring(start, end) function
Return the substring between 'start' and 'end'. Indices outside the range are clamped. If 'end' < 'start', they swap.
start: The starting index (0-based).
end: The ending index (exclusive).
Returns: The extracted substring.
substr(start, length) function
Return the substring from 'start' for 'length' characters. Negative 'start' counts from the end. This method is deprecated but still supported in many engines.
start: The starting index.
length: The number of characters to extract.
Returns: The extracted substring.
slice(start, end) function
Extract a section of the string from 'start' up to (but not including) 'end', and return it as a new string. Supports negative indices.
start: The starting index. Negative values count from the end.
end: The ending index (exclusive). Negative values count from the end.
Returns: The extracted slice.
repeat(count) function
Construct and return a new string which contains the specified number of copies of the calling string, concatenated together.
count: The number of times to repeat the string (must be >= 0).
Returns: A new repeated string.
replace(searchValue, replaceValue) function
Return a new string where the first match (or all matches if 'searchValue' is a global RegExp) of 'searchValue' is replaced by 'replaceValue'. If 'searchValue' is a string, only the first occurrence is replaced.
searchValue: A string or RegExp to match.
replaceValue: The replacement string or function.
Returns: A new string with the matched substring(s) replaced.
replaceAll(searchValue, replaceValue) function
Return a new string where all (non-overlapping) occurrences of 'searchValue' are replaced by 'replaceValue'. If 'searchValue' is a string, each exact match is replaced.
searchValue: A string or RegExp with the 'g' flag.
replaceValue: The replacement string or function.
Returns: A new string with all matches replaced.
padEnd(maxLength, padString) function
Pad the string from the end with the given 'padString' so its length reaches 'maxLength'. The result is a new string.
maxLength: The desired length of the resulting string.
padString: The string to pad with (default ' ').
Returns: A new string padded at the end.
padStart(maxLength, padString) function
Pad the string from the start with the given 'padString' so its length reaches 'maxLength'. The result is a new string.
maxLength: The desired length of the resulting string.
padString: The string to pad with (default ' ').
Returns: A new string padded at the start.
trim() function
Return a new string with whitespace trimmed from the start and end of this string.
Returns: The trimmed string.
trimEnd() function
Alias for trimEnd(). Remove trailing whitespace from the string.
Returns: The string without trailing whitespace.
trimRight() function
Alias for trimEnd(). Remove trailing whitespace from the string.
Returns: The string without trailing whitespace.
trimStart() function
Alias for trimStart(). Remove leading whitespace from the string.
Returns: The string without leading whitespace.
trimLeft() function
Alias for trimStart(). Remove leading whitespace from the string.
Returns: The string without leading whitespace.
toString() function
Return a string representing the specified object (itself). Usually called implicitly. Overrides Object.prototype.toString.
Returns: The string itself.
valueOf() function
Return the primitive string value of this String object.
Returns: The primitive string value.
__quote() function
(Non-standard) Return a quoted representation of the string, typically for debug or serialization. Implementation details may vary.
Returns: A quoted version of the string.
localeCompare(compareString) function
Return a number indicating whether this string is less than, equal to, or greater than 'compareString' in sort order, according to the current locale.
compareString: The string to compare against.
Returns: A negative number if less, 0 if the same, or a positive number if greater.
toLowerCase() function
Return a new string with all alphabetic characters converted to lowercase.
Returns: The lowercase version of this string.
toUpperCase() function
Return a new string with all alphabetic characters converted to uppercase.
Returns: The uppercase version of this string.
toLocaleLowerCase() function
Return a locale-aware lowercase version of this string, using the host's current locale or the specified locale if supported.
Returns: The locale-sensitive lowercase string.
toLocaleUpperCase() function
Return a locale-aware uppercase version of this string, using the host's current locale or the specified locale if supported.
Returns: The locale-sensitive uppercase string.
anchor(name) function
Return a string representing an HTML element with a 'name' attribute set to the current string.
name: The name attribute for the anchor.
Returns: An HTML ... string.
big() function
Return a string representing an HTML element containing the current string.
Returns: An HTML ... string.
blink() function
Return a string representing an HTML
Returns: An HTML string.
bold() function
Return a string representing an HTML element containing the current string in bold.
Returns: An HTML ... string.
fixed() function
Return a string representing an HTML element containing the current string in fixed-width font.
Returns: An HTML ... string.
fontcolor(color) function
Return a string representing an HTML element with a 'color' attribute, containing the current string.
color: The color value for the 'font' element.
Returns: An HTML ... string.
fontsize(size) function
Return a string representing an HTML element with a 'size' attribute, containing the current string.
size: The size value for the 'font' element.
Returns: An HTML ... string.
italics() function
Return a string representing an HTML element containing the current string in italics.
Returns: An HTML ... string.
link(url) function
Return a string representing an HTML element with an 'href' attribute set to the current string.
url: The URL for the 'href' attribute.
Returns: An HTML ... string.
small() function
Return a string representing an HTML element containing the current string.
Returns: An HTML ... string.
strike() function
Return a string representing an HTML element containing the current
string with strike-through.
Returns: An HTML ... string.
sub() function
Return a string representing an HTML element containing the current string as subscript.
Returns: An HTML ... string.
sup() function
Return a string representing an HTML element containing the current string as superscript.
Returns: An HTML ... string.
rm(index, endidx) function
Remove characters from this string between 'index' (inclusive) and 'endidx' (exclusive). If 'endidx' is omitted, it defaults to 'index + 1'.
index: The starting index to remove.
endidx: The ending index (exclusive).
Returns: A new string with the specified characters removed.
tolast(val) function
Return the substring of this string up to the last occurrence of 'val'. If 'val' is not found, the entire string is returned.
val: The substring to locate from the end.
Returns: A substring up to the last occurrence of 'val'.
dir() function
Return everything before the last slash ('/') in the string. If no slash is found, return an empty string.
Returns: The directory portion of the path.
next(char, from) function
Search for the next occurrence of 'char' in this string, starting at 'from'. If 'char' is an array, any of those characters qualifies. Return the matching index, or -1 if none is found.
char: A character (or array of characters) to locate.
from: The index to start from.
Returns: The index of the next occurrence, or -1 if not found.
prev(char, from, count) function
Search for the previous occurrence of 'char' before index 'from'. If 'count' is greater than 1, skip multiple occurrences going backward. Return the found index or 0 if not found.
char: The character to locate.
from: The index to start from (defaults to the end of the string).
count: How many occurrences to skip backward (default 0).
Returns: The index of the previous occurrence, or 0 if not found.
strip_ext() function
Return the string up to (but not including) the last '.' character. If '.' is not found, the entire string is returned.
Returns: The string without its last extension.
ext() function
Return the substring after the last '.' in this string. If '.' is not found, return an empty string.
Returns: The file extension or an empty string.
up_path() function
Go up one directory level from the current path, preserving the file name at the end.
Returns: A new path string one directory up, with the base filename preserved.
fromlast(val) function
Return the substring that appears after the last occurrence of 'val'. If 'val' is not found, an empty string is returned.
val: The substring to locate.
Returns: The substring after the last occurrence of 'val'.
tofirst(val) function
Return the substring from the start of this string up to the first occurrence of 'val' (excluded). If 'val' is not found, the entire string is returned.
val: The substring to locate.
Returns: A substring up to the first occurrence of 'val'.
fromfirst(val) function
Return the substring after the first occurrence of 'val'. If 'val' is not found, the entire string is returned.
val: The substring to locate.
Returns: The substring after 'val', or the entire string if 'val' not found.
name() function
Return the "name" portion of the path without extension. If no slash is found, it's up to the last '.' in the entire string. If there is a slash, it's from the last slash up to (but not including) the last '.'.
Returns: The name portion of the path without extension.
set_name(name) function
Set the base name (excluding extension) of the path to 'name', preserving the original directory and extension.
name: The new name to use.
Returns: A new path string with the updated name.
base() function
Return the portion of this string after the last '/' character. If no '/' is present, the entire string is returned.
Returns: The base name of the path.
updir() function
Go up one directory from the current path, removing the last directory name. If the path ends with a slash, remove it first. Then remove the final directory.
Returns: A new string representing one directory level up.