Arrays#

An Array is an ordered collection of values that can have elements dynamically added or removed. Arrays are very useful when you need to manage a set of similar data — for example, closing prices of the most recent N bars, or the positions of multiple signal markers.

Creating Arrays#

array.new#

Use array.new<type>() to create an empty array of a specified type:

prices  = array.new<float>()   // float array
flags   = array.new<bool>()    // boolean array
labels  = array.new<string>()  // string array

Create an array with an initial size and default value:

// Create an array of length 5, all initialized to 0.0
prices = array.new<float>(5, 0.0)

array.from#

Create an array directly from known values (the most convenient method):

levels = array.from(100.0, 105.0, 110.0, 95.0, 90.0)

Adding and Removing Elements#

Function	Description
`array.push(id, value)`	Add an element to the end of the array
`array.unshift(id, value)`	Add an element to the beginning of the array
`array.pop(id)`	Remove and return the last element
`array.shift(id)`	Remove and return the first element
`array.remove(id, index)`	Remove the element at the specified index
`array.clear(id)`	Clear the entire array

//@version=6
indicator("Array Add/Remove")

var recentCloses = array.new<float>()

// Push the latest close on every bar, keeping at most 5 elements
array.push(recentCloses, close)
if array.size(recentCloses) > 5
    array.shift(recentCloses)  // Remove the oldest

// Display array size
plot(array.size(recentCloses), "Array Size")

Reading and Modifying Elements#

Function	Description
`array.get(id, index)`	Get the value at a specified index
`array.set(id, index, value)`	Set the value at a specified index
`array.size(id)`	Return the array length
`array.first(id)`	Get the first element
`array.last(id)`	Get the last element

levels = array.from(90.0, 95.0, 100.0, 105.0, 110.0)

firstLevel = array.first(levels)   // 90.0
lastLevel  = array.last(levels)    // 110.0
thirdLevel = array.get(levels, 2)  // 100.0 (index starts at 0)

array.set(levels, 2, 101.0)        // Change the 3rd element to 101.0

Statistical Functions#

Pine Script provides a set of array statistical functions:

Function	Description
`array.avg(id)`	Average
`array.sum(id)`	Sum
`array.max(id)`	Maximum
`array.min(id)`	Minimum
`array.stdev(id)`	Standard deviation
`array.median(id)`	Median
`array.mode(id)`	Mode

//@version=6
indicator("Array Statistics")

var closes = array.new<float>()
array.push(closes, close)
if array.size(closes) > 20
    array.shift(closes)

if array.size(closes) == 20
    plot(array.avg(closes),   "Average",  color=color.blue)
    plot(array.max(closes),   "Max",      color=color.green)
    plot(array.min(closes),   "Min",      color=color.red)
    plot(array.stdev(closes), "Std Dev",  color=color.purple)

Sorting and Searching#

prices = array.from(30.0, 10.0, 50.0, 20.0, 40.0)

// Sort (modifies the original array)
array.sort(prices, order.ascending)   // ascending:  10, 20, 30, 40, 50
array.sort(prices, order.descending)  // descending: 50, 40, 30, 20, 10

// Search
idx      = array.indexof(prices, 30.0)      // Returns index of 30.0, or -1 if not found
contains = array.includes(prices, 30.0)     // true / false

Copying and Combining#

original = array.from(1.0, 2.0, 3.0)

// Copy the array
copied = array.copy(original)

// Append another array to the end
extra = array.from(4.0, 5.0)
array.concat(original, extra)  // original becomes [1, 2, 3, 4, 5]

Practical Example: Dynamic Support/Resistance Levels#

//@version=6
indicator("Dynamic Support/Resistance", overlay=true)

lookback  = input.int(50, "Lookback Bars")
threshold = input.float(0.5, "Merge Threshold (%)", step=0.1) / 100

// Collect recent pivot highs and lows
var levels = array.new<float>()

// Check each bar for pivot points
isPivotHigh = ta.pivothigh(high, 3, 3)
isPivotLow  = ta.pivotlow(low, 3, 3)

if not na(isPivotHigh)
    array.push(levels, isPivotHigh)
if not na(isPivotLow)
    array.push(levels, isPivotLow)

// Keep only the most recent 20 key price levels
while array.size(levels) > 20
    array.shift(levels)

// Draw all key price levels
if barstate.islast
    for level in levels
        line.new(bar_index - lookback, level, bar_index, level,
                 color=color.new(color.gray, 50), width=1)

Reference#

Arrays — Pine Script Official Docs