# Functions ```yaml aliases: description: This page details the functions used in Obsidian Bases to manipulate data from properties in filters and formulas. mobile: true permalink: bases/functions publish: true ``` Functions are used in [Bases](/content/help/bases/index.html) to manipulate data from [properties](/content/help/properties/index.html) in [filters](/content/help/bases/views#Filters/index.html) and [formulas](/content/help/formulas/index.html). See the [bases syntax](/content/help/bases/syntax/index.html) reference to learn more about how you can use functions. Bases functions follow JavaScript behavior. For complete reference documentation, refer to [MDN Web Docs](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference). Aside from [Global](/content/help/bases/functions#Global/index.html) functions, most functions depend on the type of value you want to modify: - [Any](/content/help/bases/functions#Any%20type/index.html) - [Date](/content/help/bases/functions#Date%20type/index.html) - [String](/content/help/bases/functions#String%20type/index.html) - [Number](/content/help/bases/functions#Number%20type/index.html) - [List](/content/help/bases/functions#List%20type/index.html) - [Link](/content/help/bases/functions#Link%20type/index.html) - [File](/content/help/bases/functions#File%20type/index.html) - [Object](/content/help/bases/functions#Object%20type/index.html) - [Regular expression](/content/help/bases/functions#Regular%20expression%20type/index.html) ## Global Global functions are used without a type. ### `escapeHTML()` `escapeHTML(html: string): string` - Escapes special characters in a string to make it safe for inclusion in HTML. ### `date()` `date(date: string): date` - `date(string): date` parses the provided string and returns a date object. - The `date` string should be in the format `YYYY-MM-DD HH:mm:ss`. ### `duration()` `duration(value: string): duration` - Parses a string as a duration. See the [date arithmetic section](/content/help/bases/syntax#Date%20arithmetic/index.html) for the `value` string format. - Explicit parsing is not needed for date arithmetic (for example, `now() + '1d'`), but is needed when performing arithmetic on durations (for example, `now() + (duration('1d') * 2)`). - When performing arithmetic on durations with scalars, the duration must be on the left. For example `duration('5h') * 2`, instead of `2 * duration('5h')`. ### `file()` `file(path: string | file | url): file` - Returns a file object for the given file or path. - Example: `file(link("[[filename]]"))` or `file("path to file")`. ### `html()` `html(html: string): html` - Converts a string into a code snippet that renders as HTML. ### `if()` `if(condition: any, trueResult: any, falseResult?: any): any` - `condition` is the expression to evaluate. - `trueResult` is the output if `condition` is true. - `falseResult` is the optional output if `condition` is false. If omitted, defaults to `null`. - Returns `trueResult` if `condition` is true or truthy, otherwise returns `falseResult`. - Example: `if(isModified, "Modified", "Unmodified")` ### `image()` `image(path: string | file | url): image` - Returns an image object that renders the image in the view. - Example: `image(image-property)` or `image("https://obsidian.md/images/obsidian-logo-gradient.svg")`. ### `icon()` `icon(name: string): icon` - Returns a value that will render as an icon in a view. The icon name must match a supported Lucide icon. - Example: `icon("arrow-right")`. ### `link()` `link(path: string | file, display?: value): Link` - Parses a string `path` and returns a Link object that renders as a link to the given path. - Optionally provide the `display` parameter to set the link display text. ### `list()` `list(element: any): List` - If the provided element is a list, returns it unmodified. - Otherwise, wraps the provided `element` in a list, creating a list with a single element. - Use this function when a property contains a mix of strings or lists across the vault. - Example: `list("value")` returns `[{"value"}]`. ### `max()` `max(value1: number, value2: number...): number` - Returns the largest of all the provided numbers. ### `min()` `min(value1: number, value2: number...): number` - Returns the smallest of all the provided numbers. ### `now()` `now(): date` - Returns a date object for the current moment. ### `number()` `number(input: any): number` - Attempts to return the provided value as a number. - Returns date objects as milliseconds since the Unix epoch. - Returns booleans as `1` or `0`. - Parses strings as numbers, and returns an error if the string is not a valid number. - Example: `number("3.4")` returns `3.4`. ### `today()` `today(): date` - Returns a date object for the current date. The time portion is set to midnight. ### `random()` `random(): number` - Returns a random number between 0 and 1. - The number generation refreshes whenever a view is loaded. Navigating between views changes the random number. ## Any type Functions you can use with any value. This includes strings (e.g. `"hello"`), numbers (e.g. `42`), lists (e.g. `[1,2,3]`), objects, and more. ### `isTruthy()` `any.isTruthy(): boolean` - Returns the value coerced into a boolean. - Example: `1.isTruthy()` returns `true`. ### `isType()` `any.isType(type: string): boolean` - Returns true if the value is of the provided type. - Example: `"example".isType("string")` and `true.isType("boolean")` both return true. ### `toString()` `any.toString(): string` - Returns the string representation of any value. - Example: `123.toString()` returns `"123"`. ## Date type Functions you can use with a date and time such as `date("2025-05-27")`. Date comparisons can be done using [date arithmetic](/content/help/bases/syntax#Date%20arithmetic/index.html). ### Fields The following fields are available for dates: | Field | Type | Description | | --- | --- | --- | | `date.year` | `number` | The year of the date | | `date.month` | `number` | The month of the date (1–12) | | `date.day` | `number` | The day of the month | | `date.hour` | `number` | The hour (0–23) | | `date.minute` | `number` | The minute (0–59) | | `date.second` | `number` | The second (0–59) | | `date.millisecond` | `number` | The millisecond (0–999) | ### `date()` `date.date(): date` - Returns a date object with the time removed. - Example: `now().date().format("YYYY-MM-DD HH:mm:ss")` returns a string such as "2025-12-31 00:00:00". ### `format()` `date.format(format: string): string` - `format` is the format string (e.g., "YYYY-MM-DD"). - Returns the date formatted as specified by a Moment.js format string. - Example: `date.format("YYYY-MM-DD")` returns `"2025-05-27"`. ### `time()` `date.time(): string` - Returns the time portion as a string. - Example: `now().time()` returns a string such as "23:59:59". ### `relative()` `date.relative(): string` - Returns a readable comparison of the date to the current datetime. - Example: `file.mtime.relative()` returns a value such as `3 days ago`. ### `isEmpty()` `date.isEmpty(): boolean` - Returns false. ## String type Functions you can use with a sequence of characters such as `"hello"`. ### Fields | Field | Type | Description | | --- | --- | --- | | `string.length` | `number` | The number of characters in the string | ### `contains()` `string.contains(value: string): boolean` - `value` is the substring to search for. - Returns true if the string contains `value`. - Example: `"hello".contains("ell")` returns `true`. ### `containsAll()` `string.containsAll(...values: string): boolean` - `values` are one or more substrings to search for. - Returns true if the string contains all of the `values`. - Example: `"hello".containsAll("h", "e")` returns `true`. ### `containsAny()` `string.containsAny(...values: string): boolean` - `values` are one or more substrings to search for. - Returns true if the string contains at least one of the `values`. - Example: `"hello".containsAny("x", "y", "e")` returns `true`. ### `endsWith()` `string.endsWith(query: string): boolean` - `query` is the string to check at the end. - Returns true if this string ends with `query`. - Example: `"hello".endsWith("lo")` returns `true`. ### `isEmpty()` `string.isEmpty(): boolean` - Returns true if the string has no characters, or is not present. - Example: `"Hello world".isEmpty()` returns `false`. - Example: `"".isEmpty()` returns `true`. ### `lower()` `string.lower(): string` - Returns the string converted to lower case. ### `replace()` `string.replace(pattern: string | Regexp, replacement: string): string` - `pattern` is the value to search for in the target string. - `replacement` is the value to replace found patterns with. When `pattern` is a Regexp, you can reference capture groups in `replacement` using `$1`, `$2`, and so on. - If `pattern` is a string, all occurrences of the pattern will be replaced. - If `pattern` is a Regexp, the `g` flag determines if only the first or if all occurrences are replaced. - Example: `"a:b:c:d".replace(/:/, "-")` returns `"a-b:c:d"`, whereas `"a:b:c:d".replace(/:/g, "-")` returns `"a-b-c-d"`. - Example with capture groups: `"John Smith".replace(/(\w+) (\w+)/, "$2, $1")` returns `"Smith, John"`. ### `repeat()` `string.repeat(count: number): string` - `count` is the number of times to repeat the string. - Example: `"123".repeat(2)` returns `"123123"`. ### `reverse()` `string.reverse(): string` - Reverses the string. - Example: `"hello".reverse()` returns `"olleh"`. ### `slice()` `string.slice(start: number, end?: number): string` - `start` is the inclusive start index. - `end` is the optional exclusive end index. - Returns a substring from `start` (inclusive) to `end` (exclusive). - Example: `"hello".slice(1, 4)` returns `"ell"`. - If `end` is omitted, slices to the end of the string. ### `split()` `string.split(separator: string | Regexp, n?: number): list` - `separator` is the delimiter for splitting the string. - `n` is an optional number. If provided, the result will have the first `n` elements. - Returns a list of substrings. - Example: `"a,b,c,d".split(",", 3)` or `"a,b,c,d".split(/,/, 3)` returns `["a", "b", "c"]`. ### `startsWith()` `string.startsWith(query: string): boolean` - `query` is the string to check at the beginning. - Returns true if this string starts with `query`. - Example: `"hello".startsWith("he")` returns `true`. ### `title()` `string.title(): string` - Converts the string to title case (first letter of each word capitalized). - Example: `"hello world".title()` returns `"Hello World"`. ### `trim()` `string.trim(): string` - Removes whitespace from both ends of the string. - Example: `" hi ".trim()` returns `"hi"`. ## Number type Functions you can use with numeric values such as `42`, `3.14`. ### `abs()` `number.abs(): number` - Returns the absolute value of the number. - Example: `(-5).abs()` returns `5`. ### `ceil()` `number.ceil(): number` - Rounds the number up to the nearest integer. - Example: `(2.1).ceil()` returns `3`. ### `floor()` `number.floor(): number` - Rounds the number down to the nearest integer. - Example: `(2.9).floor()` returns `2`. ### `isEmpty()` `number.isEmpty(): boolean` - Returns true if the number is not present. - Example: `5.isEmpty()` returns `false`. ### `round()` `number.round(digits: number): number` - Rounds the number to the nearest integer. - Optionally, provide a `digits` parameter to round to that number of decimal places. - Example: `(2.5).round()` returns `3`, and `(2.3333).round(2)` returns `2.33`. ### `toFixed()` `number.toFixed(precision: number): string` - `precision` is the number of decimal places. - Returns a string with the number in fixed-point notation. - Example: `(3.14159).toFixed(2)` returns `"3.14"`. ## List type Functions you can use with an ordered list of elements such as `[1, 2, 3]`. ### Fields | Field | Type | Description | | --- | --- | --- | | `list.length` | `number` | The number of elements in the list | ### `contains()` `list.contains(value: any): boolean` - `value` is the element to search for. - Returns true if the list contains `value`. - Example: `[1,2,3].contains(2)` returns `true`. ### `containsAll()` `list.containsAll(...values: any): boolean` - `values` are one or more elements to search for. - Returns true if the list contains all of the `values`. - Example: `[1,2,3].containsAll(2,3)` returns `true`. ### `containsAny()` `list.containsAny(...values: any): boolean` - `values` are one or more elements to search for. - Returns true if the list contains at least one of the `values`. - Example: `[1,2,3].containsAny(3,4)` returns `true`. ### `filter()` `list.filter(value: Boolean): list` - Filters the list and keeps only elements where the expression is true. - `value` is the value of an item in the list. - `index` is the index of the current value. - Example: `[1,2,3,4].filter(value > 2)` returns `[3,4]`. ### `flat()` `list.flat(): list` - Flattens a nested list into a single list. - Example: `[1,[2,3]].flat()` returns `[1,2,3]`. ### `isEmpty()` `list.isEmpty(): boolean` - Returns true if the list has no elements. - Example: `[1,2,3].isEmpty()` returns `false`. ### `join()` `list.join(separator: string): string` - `separator` is the string to insert between elements. - Joins all list elements into a single string. - Example: `[1,2,3].join(",")` returns `"1,2,3"`. ### `map()` `list.map(value: Any): list` - Transforms each element of the list using an expression. - `value` is the value of an item in the list. - `index` is the index of the current value. - Example: `[1,2,3,4].map(value + 1)` returns `[2,3,4,5]`. ### `reduce()` `list.reduce(expression: Any, acc: Any): Any` - Reduces the list to a single value by running an expression for each element. The expression must return the next value of `acc`. Use `value` for the current element, `index` for its position, and `acc` for the accumulated result so far. - `expression` is evaluated for every element in the list. - Example (sum): `[1,2,3].reduce(acc + value, 0)` returns `6`. - Example (max): `values.filter(value.isType("number")).reduce(if(acc == null || value > acc, value, acc), null)` returns the largest number, or `null` if none. ### `reverse()` `list.reverse(): list` - Reverses the list in place. - Example: `[1,2,3].reverse()` returns `[3,2,1]`. ### `slice()` `list.slice(start: number, end?: number): list` - `start` is the inclusive start index. - `end` is the optional exclusive end index. - Returns a shallow copy of a portion of the list from `start` (inclusive) to `end` (exclusive). - Example: `[1,2,3,4].slice(1,3)` returns `[2,3]`. - If `end` is omitted, slices to the end of the list. ### `sort()` `list.sort(): list` - Sorts list elements from smallest to largest. - Example: `[3, 1, 2].sort()` returns `[1, 2, 3]`. - Example: `[`c`, `a`, `b`].sort()` returns `[`a`, `b`, `c`]`. ### `unique()` `list.unique(): list` - Removes duplicate elements. - Example: `[1,2,2,3].unique()` returns `[1,2,3]`. ## Link type Functions you can use on a link. Links can be created from a file (`file.asLink()`) or a path (`link("path")`). ### `asFile()` `link.asFile(): file` - Returns a file object if the link refers to a valid local file. - Example: `link("[[filename]]").asFile()`. ### `linksTo()` `link.linksTo(file): boolean` - Returns `true` if the file represented by `link` has a link to `file`. ## File type Functions you can use with a file in the vault. ### Fields The following fields are available for files: | Field | Type | Description | | --- | --- | --- | | `file.name` | `string` | The name of this file. | | `file.basename` | `string` | The name of this file without the file extension. | | `file.path` | `string` | The full path to this file, relative to the vault root. | | `file.folder` | `string` | The full path to the parent folder. | | `file.ext` | `string` | The file extension for this file. | | `file.size` | `number` | The size of this file, in bytes. | | `file.properties` | `object` | The note properties for this file. | | `file.tags` | `list` | The tags for this file. Includes inline tags. | | `file.links` | `list` | The internal links within this file. | | `file.ctime` | `date` | Timestamp of when this file was created. | | `file.mtime` | `date` | Timestamp of when this file was last modified. | ### `asLink()` `file.asLink(display?: string): Link` - `display` is optional display text for the link. - Returns a Link object that renders as a functioning link. - Example: `file.asLink()` ### `hasLink()` `file.hasLink(otherFile: file | string): boolean` - `otherFile` is another file object or string path to check. - Returns true if `file` links to `otherFile`. - Example: `file.hasLink(otherFile)` returns `true` if there’s a link from `file` to `otherFile`. ### `hasProperty()` `file.hasProperty(name: string): boolean` - Returns `true` if the file has the given property. ### `hasTag()` `file.hasTag(...values: string): boolean` - `values` are one or more tag names. - Returns true if the file has any of the tags in `values`. - Example: `file.hasTag("tag1", "tag2")` returns `true` if the file has tag `#tag1` or `#tag2`. It also includes any [nested tags](/content/help/tags#Nested%20tags/index.html), such as `#tag1/a` or `#tag2/b`. ### `inFolder()` `file.inFolder(folder: string): boolean` - `folder` is the folder name to check. - Returns true if the file is in the specified folder or one of its sub-folders. - Example: `file.inFolder("notes")` returns `true`.