cheat-sheet.md

April 11, 2026 · View on GitHub

{% raw %}

Quick reference for all 55+ templjs built-in functions. Use pipe syntax in templates: {{ value | functionName(args) }}.

String Functions (20)

Function	Signature	Example
`upper`	`upper()`	`"hello" \| upper` → `"HELLO"`
`lower`	`lower()`	`"HELLO" \| lower` → `"hello"`
`capitalize`	`capitalize()`	`"hello" \| capitalize` → `"Hello"`
`trim`	`trim()`	`" hi " \| trim` → `"hi"`
`ltrim`	`ltrim()`	`" hi " \| ltrim` → `"hi "`
`rtrim`	`rtrim()`	`" hi " \| rtrim` → `" hi"`
`replace`	`replace(search, replacement)`	`"hello" \| replace("l", "r")` → `"herro"`
`slice`	`slice(start[, end])`	`"hello" \| slice(0, 3)` → `"hel"`
`split`	`split(delimiter)`	`"a,b" \| split(",")` → `["a","b"]`
`join`	`join(separator)`	`["a","b"] \| join(",")` → `"a,b"`
`startsWith`	`startsWith(prefix)`	`"hello" \| startsWith("he")` → `true`
`endsWith`	`endsWith(suffix)`	`"hello" \| endsWith("lo")` → `true`
`includes`	`includes(substring)`	`"hello world" \| includes("world")` → `true`
`indexOf`	`indexOf(substring)`	`"hello" \| indexOf("ll")` → `2`
`padStart`	`padStart(length[, char])`	`"5" \| padStart(3, "0")` → `"005"`
`padEnd`	`padEnd(length[, char])`	`"5" \| padEnd(3, "0")` → `"500"`
`repeat`	`repeat(count)`	`"ab" \| repeat(3)` → `"ababab"`
`reverse`	`reverse()`	`"hello" \| reverse` → `"olleh"`
`escape`	`escape()`	`"<b>" \| escape` → `"<b>"`
`truncate`	`truncate(length[, suffix])`	`"hello world" \| truncate(5)` → `"hello..."`

Number Functions (23)

Function	Signature	Example
`round`	`round([decimals])`	`3.14159 \| round(2)` → `3.14`
`floor`	`floor()`	`3.7 \| floor` → `3`
`ceil`	`ceil()`	`3.2 \| ceil` → `4`
`abs`	`abs()`	`-5 \| abs` → `5`
`min`	`min(b[, ...])` or `min(array)`	`min(5, 2, 8)` → `2`
`max`	`max(b[, ...])` or `max(array)`	`max(5, 2, 8)` → `8`
`clamp`	`clamp(min, max)`	`5 \| clamp(1, 3)` → `3`
`sqrt`	`sqrt()`	`16 \| sqrt` → `4`
`pow`	`pow(exponent)`	`2 \| pow(3)` → `8`
`log`	`log([base])`	`8 \| log(2)` → `3`
`exp`	`exp()`	`1 \| exp` → `2.718...`
`sin`	`sin()`	`0 \| sin` → `0`
`cos`	`cos()`	`0 \| cos` → `1`
`tan`	`tan()`	`0 \| tan` → `0`
`sign`	`sign()`	`-5 \| sign` → `-1`
`toFixed`	`toFixed(decimals)`	`3.14159 \| toFixed(2)` → `"3.14"`
`parseInt`	`parseInt([radix])`	`"42" \| parseInt` → `42`
`parseFloat`	`parseFloat()`	`"3.14" \| parseFloat` → `3.14`
`isNaN`	`isNaN()`	`NaN \| isNaN` → `true`
`isFinite`	`isFinite()`	`42 \| isFinite` → `true`
`sum`	`sum(array)`	`[1,2,3] \| sum` → `6`
`avg`	`avg(array)`	`[2,4,6] \| avg` → `4`
`product`	`product(array)`	`[2,3,4] \| product` → `24`

Datetime Functions (15)

Function	Signature	Example
`now`	`now()`	`now()` → Unix ms timestamp
`format`	`format(pattern[, tz])`	`ts \| format("YYYY-MM-DD")` → `"2024-02-18"`
`parse`	`parse(string, pattern)`	`"2024-02-18" \| parse("YYYY-MM-DD")` → timestamp
`timestamp`	`timestamp(isoString)`	`"2024-02-18T12:00:00Z" \| timestamp` → ms
`toISO`	`toISO()`	`ts \| toISO` → `"2024-02-18T12:00:00.000Z"`
`fromISO`	`fromISO()`	`"2024-02-18T12:00:00.000Z" \| fromISO` → ms
`addDays`	`addDays(n)`	`ts \| addDays(5)` → ts+5days
`addHours`	`addHours(n)`	`ts \| addHours(3)` → ts+3hrs
`addMinutes`	`addMinutes(n)`	`ts \| addMinutes(30)` → ts+30min
`diff`	`diff(other)`	`ts \| diff(ts2)` → ms difference
`getYear`	`getYear()`	`ts \| getYear` → `2024`
`getMonth`	`getMonth()`	`ts \| getMonth` → `1` (0-indexed)
`getDay` / `getDate`	`getDay()`	`ts \| getDay` → `18`
`getHour`	`getHour()`	`ts \| getHour` → `12`
`getDayOfWeek`	`getDayOfWeek()`	`ts \| getDayOfWeek` → `0` (0=Sun)
`timezone`	`timezone(tz)`	`ts \| timezone("America/New_York")` → formatted string

Array Functions (19)

Function	Signature	Example
`length`	`length()`	`[1,2,3] \| length` → `3`
`size`	`size()`	`[1,2,3] \| size` → `3` (alias)
`first`	`first()`	`[1,2,3] \| first` → `1`
`last`	`last()`	`[1,2,3] \| last` → `3`
`nth`	`nth(index)`	`["a","b","c"] \| nth(1)` → `"b"`
`reverse`	`reverse()`	`[1,2,3] \| reverse` → `[3,2,1]`
`sort`	`sort([key])`	`[3,1,2] \| sort` → `[1,2,3]`
`unique`	`unique()`	`[1,2,2,3] \| unique` → `[1,2,3]`
`filter`	`filter(predicate)`	`items \| filter("active")`
`map`	`map(fn\|key)`	`users \| map("name")` → names array
`reduce`	`reduce(fn, initial)`	`[1,2,3] \| reduce("+", 0)` → `6`
`find`	`find(predicate)`	`users \| find("id == 1")` → first match
`includes`	`includes(value)`	`[1,2,3] \| includes(2)` → `true`
`indexOf`	`indexOf(value)`	`[1,2,3] \| indexOf(2)` → `1`
`slice`	`slice(start[, end])`	`[1,2,3,4] \| slice(1, 3)` → `[2,3]`
`concat`	`concat(other)`	`[1,2] \| concat([3,4])` → `[1,2,3,4]`
`flatten`	`flatten([depth])`	`[[1,2],[3]] \| flatten` → `[1,2,3]`
`where`	`where(key)`	`items \| where("published")` → truthy items
`join`	`join(separator)`	`[1,2,3] \| join(",")` → `"1,2,3"`

Object Functions (11)

Function	Signature	Example
`keys`	`keys()`	`{a:1,b:2} \| keys` → `["a","b"]`
`values`	`values()`	`{a:1,b:2} \| values` → `[1,2]`
`entries`	`entries()`	`{a:1} \| entries` → `[["a",1]]`
`has`	`has(key)`	`{a:1} \| has("a")` → `true`
`get`	`get(path[, default])`	`obj \| get("a.b", 0)` → value or 0
`merge`	`merge(other)`	`{a:1} \| merge({b:2})` → `{a:1,b:2}`
`assign`	`assign(other)`	`{a:1} \| assign({b:2})` → `{a:1,b:2}`
`pick`	`pick(keys)`	`obj \| pick(["a","c"])` → subset
`omit`	`omit(keys)`	`obj \| omit(["b"])` → obj without b
`length`	`length()`	`{a:1,b:2} \| length` → `2`
`isEmpty`	`isEmpty()`	`{} \| isEmpty` → `true`

Utility Functions (6)

Function	Signature	Example
`default`	`default(fallback)`	`null \| default("Guest")` → `"Guest"`
`fallback`	`fallback(value)`	alias for `default`
`typeof`	`typeof()`	`123 \| typeof` → `"number"`
`string`	`string()`	`123 \| string` → `"123"`
`number`	`number([default])`	`"42" \| number` → `42`
`json`	`json()`	`{a:1} \| json` → `'{"a":1}'`

Filter Pipe Syntax

{{ value | filter }}
{{ value | filter(arg1, arg2) }}
{{ value | filter1 | filter2(arg) }}

Expression Predicates

filter, find, and where accept expression strings:

{{ scores | filter("> 90") }}
{{ users | find("active == true") }}
{{ items | where("published") }}

Quick Path Reference

{{ user.name }}          {{/* dot notation */}}
{{ items[0] }}           {{/* array index */}}
{{ items[idx] }}         {{/* variable index */}}
{{ map["key name"] }}    {{/* quoted key */}}