//@version=5 indicator("Lesson 6 - Conditional logic", overlay=true) ema50 = ta.ema(close, 50) // Classify the regime on every bar (chained ternary). regime = close > ema50 ? "uptrend" : close < ema50 ? "downtrend" : "range" plot(ema50, "EMA 50", color=color.orange, linewidth=2) plot(close, "Close", color = regime == "uptrend" ? color.green : regime == "downtrend" ? color.red : color.gray) // Persistent state — survives across bars, unlike a plain if. var bool inLong = false if not inLong and close > ema50 inLong := true else if inLong and close < ema50 inLong := false bgcolor(inLong ? color.new(color.green, 92) : color.new(color.red, 92)) plotshape(inLong and not inLong[1], "Enter long", shape.triangleup, location.belowbar, color=color.green) plotshape(not inLong and inLong[1], "Exit long", shape.triangledown, location.abovebar, color=color.red)

if/else blocks

Pine's if statement works on series — the branch is taken bar by bar. A common pattern:

signal = close > ta.ema(close, 50) ? 1 : -1

This assigns 1 when close is above the 50-EMA, else -1. The ternary is the cleanest form for two-way decisions.

Multi-branch if/else

For three or more branches, if/else if/else reads better:

regime = close > ta.ema(close, 200) ? "uptrend"
     : close < ta.ema(close, 200) ? "downtrend"
     : "range"

Switch expressions

Pine v5 has a switch expression that is cleaner when one variable drives the branch. The MA example from Part 1 used it:

ma = switch maType
    "SMA" => ta.sma(src, length)
    "EMA" => ta.ema(src, length)
    "WMA" => ta.wma(src, length)

State matters

Plain if only changes a variable on the bar the condition is true. If you need state that persists across bars (like "I am currently in a long"), use var:

var bool inLong = false
if not inLong and close > ta.ema(close, 50)
    inLong := true
else if inLong and close < ta.ema(close, 50)
    inLong := false

Common mistake: missing an else

Inside an if without an else, a variable assignment only takes effect on the bar the condition is true. On other bars the variable keeps its previous value — which is sometimes what you want and sometimes a bug. Be explicit.

What to remember

Series-aware if + var for persistent state is the spine of every strategy. Master it before moving to functions.