Pine Script Variable Declaration: Mastering var, varip, and Proper Initialization Across Historical Bars
Variable declaration is the foundational building block of any Pine Script indicator or strategy. Understanding the precise behavioral differences between standard assignment, var , and varip — and knowing exactly when each value is initialized or updated across historical and real-time bars — is essential for writing correct, predictable, and performant Pine Script code. 1. The Pine Script Execution Model: Why Variable Scope Matters Pine Script executes your script once per bar, from the oldest historical bar to the most recent, and then continues on each new real-time tick. This bar-by-bar execution model is the core reason why variable declaration semantics matter so much. A variable declared without var is re-evaluated and re-initialized on every single bar execution. A variable declared with var persists its value across bars. Understanding this distinction prevents the most common logical errors in Pine Script development. gra...