Arrays in Pine Script

Arrays allow you to store and manipulate collections of data. This guide covers all array operations in Pine Script.

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Why Use Arrays?

Use Case	Description
Rolling calculations	Keep history of values
Custom indicators	Build complex logic
Data structures	Store multiple values
Loops	Iterate through data

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Basic Arrays

Create Array

//@version=6
indicator("Basic Arrays")
 
// Create empty array
myArray = array.new_float()
 
// Create with values
numbers = array.new_float(0)
array.push(numbers, 10)
array.push(numbers, 20)
array.push(numbers, 30)
 
plot(close)

Array with Initial Values

//@version=6
indicator("Initial Values")
 
// Create with size
arr = array.new_float(5, 0)
 
// Set values
array.set(arr, 0, 10)
array.set(arr, 1, 20)
array.set(arr, 2, 30)
 
firstValue = array.get(arr, 0)
plot(firstValue)

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Array Functions

Adding/Getting Values

//@version=6
indicator("Array Functions")
 
arr = array.new_float(0)
 
// Push values
array.push(arr, 100)
array.push(arr, 200)
array.push(arr, 300)
 
// Get values
val0 = array.get(arr, 0)  // 100
val1 = array.get(arr, 1)  // 200
val2 = array.get(arr, 2)  // 300
 
// Array size
size = array.size(arr)  // 3
 
plot(val0)

Modifying Arrays

//@version=6
indicator("Modify Array")
 
arr = array.new_float(0)
 
// Add values
array.push(arr, 10)
array.push(arr, 20)
array.push(arr, 30)
 
// Modify
array.set(arr, 1, 25)  // Change second element
 
// Remove last
lastVal = array.pop(arr)
 
// Clear
array.clear(arr)
 
plot(close)

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Practical Examples

Rolling Maximum

//@version=6
indicator("Rolling Max")
 
var float[] priceHistory = array.new_float()
 
// Add current price to history
array.push(priceHistory, close)
 
// Keep only last 20
if array.size(priceHistory) > 20
    array.shift(priceHistory)
 
// Get max
maxPrice = array.max(priceHistory)
 
plot(maxPrice, color=color.red)

Rolling Average

//@version=6
indicator("Rolling Avg")
 
var float[] prices = array.new_float()
 
// Add price
array.push(prices, close)
 
// Limit size
if array.size(prices) > 20
    array.shift(prices)
 
// Calculate average
avg = array.avg(prices)
 
plot(avg, color=color.blue)

Standard Deviation

//@version=6
indicator("Std Dev")
 
var float[] prices = array.new_float()
 
array.push(prices, close)
if array.size(prices) > 20
    array.shift(prices)
 
mean = array.avg(prices)
variance = 0.0
 
for i = 0 to array.size(prices) - 1
    diff = array.get(prices, i) - mean
    variance := variance + diff * diff
 
stdDev = math.sqrt(variance / array.size(prices))
 
plot(stdDev, color=color.purple)

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Rolling Window Calculations

Moving Average with Array

//@version=6
indicator("Array MA")
 
length = input.int(20, "Length")
var float[] data = array.new_float()
 
array.push(data, close)
if array.size(data) > length
    array.shift(data)
 
sum = 0.0
for i = 0 to array.size(data) - 1
    sum := sum + array.get(data, i)
 
ma = sum / array.size(data)
 
plot(ma, color=color.blue)
plot(ta.sma(close, length), color=color.red)

Sum Over Period

//@version=6
indicator("Array Sum")
 
var float[] values = array.new_float()
 
array.push(values, volume)
if array.size(values) > 20
    array.shift(values)
 
totalVolume = array.sum(values)
 
plot(totalVolume, color=color.green)

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Custom Indicators with Arrays

RSI with Arrays

//@version=6
indicator("Array RSI")
 
length = input.int(14, "Length")
var float[] gains = array.new_float()
var float[] losses = array.new_float()
 
change = close - close[1]
 
if change > 0
    array.push(gains, change)
    array.push(losses, 0)
else
    array.push(gains, 0)
    array.push(losses, math.abs(change))
 
if array.size(gains) > length
    array.shift(gains)
    array.shift(losses)
 
avgGain = array.avg(gains)
avgLoss = array.avg(losses)
 
rs = avgLoss == 0 ? 100 : avgGain / avgLoss
rsi = 100 - (100 / (1 + rs))
 
plot(rsi, title="RSI")
hline(70)
hline(30)

Bollinger Bands with Arrays

//@version=6
indicator("Array BB")
 
length = input.int(20, "Length")
mult = input.float(2.0, "Multiplier")
 
var float[] prices = array.new_float()
 
array.push(prices, close)
if array.size(prices) > length
    array.shift(prices)
 
mean = array.avg(prices)
variance = 0.0
 
for i = 0 to array.size(prices) - 1
    diff = array.get(prices, i) - mean
    variance := variance + diff * diff
 
stdDev = math.sqrt(variance / array.size(prices))
 
upper = mean + mult * stdDev
lower = mean - mult * stdDev
 
plot(upper, color=color.red)
plot(mean, color=color.blue)
plot(lower, color=color.green)

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Historical Data with Arrays

Price History

//@version=6
indicator("Price History")
 
lookback = input.int(50, "Lookback")
var float[] history = array.new_float()
 
array.push(history, close)
if array.size(history) > lookback
    array.shift(history)
 
// Highest in history
highestPrice = array.max(history)
 
// Lowest in history  
lowestPrice = array.min(history)
 
// Current vs range
position = (close - lowestPrice) / (highestPrice - lowestPrice)
 
plot(highestPrice, color=color.green, title="High")
plot(lowestPrice, color=color.red, title="Low")

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Multiple Arrays

//@version=6
indicator("Multiple Arrays")
 
var float[] highs = array.new_float()
var float[] lows = array.new_float()
var float[] closes = array.new_float()
 
array.push(highs, high)
array.push(lows, low)
array.push(closes, close)
 
if array.size(highs) > 20
    array.shift(highs)
    array.shift(lows)
    array.shift(closes)
 
avgHigh = array.avg(highs)
avgLow = array.avg(lows)
avgClose = array.avg(closes)
 
plot(avgHigh, color=color.green)
plot(avgLow, color=color.red)
plot(avgClose, color=color.blue)

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Complete Example

//@version=6
indicator("Complete Array Example", overlay=true)
 
// === INPUTS ===
length = input.int(20, "Length")
mult = input.float(2.0, "Multiplier")
 
// === ARRAYS ===
var float[] prices = array.new_float()
var float[] highsArr = array.new_float()
var float[] lowsArr = array.new_float()
 
// === ADD DATA ===
array.push(prices, close)
array.push(highsArr, high)
array.push(lowsArr, low)
 
// === LIMIT SIZE ===
if array.size(prices) > length
    array.shift(prices)
    array.shift(highsArr)
    array.shift(lowsArr)
 
// === CALCULATIONS ===
avgPrice = array.avg(prices)
maxHigh = array.max(highsArr)
minLow = array.min(lowsArr)
 
// Standard deviation
variance = 0.0
for i = 0 to array.size(prices) - 1
    diff = array.get(prices, i) - avgPrice
    variance := variance + diff * diff
stdDev = math.sqrt(variance / array.size(prices))
 
// Bands
upper = avgPrice + mult * stdDev
lower = avgPrice - mult * stdDev
 
// === PLOT ===
plot(upper, color=color.red, title="Upper")
plot(avgPrice, color=color.blue, title="MA")
plot(lower, color=color.green, title="Lower")
 
// Signal
buySignal = ta.crossover(close, lower)
sellSignal = ta.crossunder(close, upper)
 
plotshape(buySignal, location=location.belowbar, style=shape.labelup, color=color.lime)
plotshape(sellSignal, location=location.abovebar, style=shape.labeldown, color=color.red)

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Array Reference

Function	Description
array.new_*()	Create array
array.push()	Add to end
array.pop()	Remove from end
array.shift()	Remove from start
array.get()	Get value at index
array.set()	Set value at index
array.size()	Get array size
array.avg()	Calculate average
array.sum()	Calculate sum
array.max()	Find maximum
array.min()	Find minimum
array.clear()	Clear all values

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Best Practices

1. Initialize with var - Keep array across bars
2. Limit size - Prevent memory issues
3. Use shift() - Remove old data
4. Check size - Before accessing elements
5. Type consistency - Use same type in array

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Next Steps

• optimization - Optimize your code
• examples - More strategies
• volume - More indicators

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Arrays unlock advanced Pine Script capabilities.