---
title: Conditionals & Loops
description: Learn how to use for loops, while loops, and conditional statements in kScript v2 for iterative calculations and control flow logic within the per-bar execution model.
---

Conditionals and loops control which code runs during each bar's calculation phase. Use them for decision-making logic, counted iteration, and conditional searches while keeping the per-bar execution model in mind.

## Overview

| Control Type | Description | Features |
| --- | --- | --- |
| **Conditional Statements** | Use `if/else` statements to execute different code paths based on conditions. Essential for decision-making logic in your indicators. | Condition-based execution, multiple branches, boolean logic |
| **For Loops** | Use `for` loops when you know the number of iterations in advance. Perfect for counted iterations and array-like processing. | Known iteration count, counter-based control, array-like processing |
| **While Loops** | Use `while` loops when the number of iterations depends on a condition. Ideal for search patterns and conditional iteration. | Condition-based control, dynamic iteration count, search patterns |

| Construct | Description |
| --- | --- |
| [`if/else`](#if-else) | Conditional execution statements |
| [`for`](#for-loop) | Counted iteration loop |
| [`while`](#while-loop) | Conditional iteration loop |

<a id="if-else"></a>

## if/else - conditional execution statements

`if (condition) { /* body */ } else { /* alternative */ }`

| Parameter | Type | Description |
| --- | --- | --- |
| `condition` | boolean expression | Expression that evaluates to true or false |
| `if body` | code block | Code executed when condition is true |
| `else body` | code block | Code executed when condition is false (optional) |

**Returns:** `void (executes conditional code)`.

```javascript
// Basic if/else with price direction
var direction = "neutral"
if (closeTs[0] > closeTs[1]) {
  direction = "up"
} else {
  direction = "down"
}
```

<a id="for-loop"></a>

## for - counted iteration loop

`for (var i = start; i < end; i = i + increment) { /* body */ }`

| Parameter | Type | Description |
| --- | --- | --- |
| `initialization` | var declaration | Initialize the loop counter variable |
| `condition` | boolean expression | Loop continues while this condition is true |
| `increment` | assignment | Update the counter variable each iteration |

**Returns:** `void (executes loop body)`.

```javascript
// Basic iteration
for (var i = 1; i <= 10; i = i + 1) {
    print("i = ", i)
}
```

<a id="while-loop"></a>

## while - conditional iteration loop

`while (condition) { /* body */ }`

| Parameter | Type | Description |
| --- | --- | --- |
| `condition` | boolean expression | Loop continues while this condition is true |

**Returns:** `void (executes loop body)`.

```javascript
// While (use sparingly due to execution limits)
var j = 0
while (j < 3) {
  print("j = ", j)
  j = j + 1
}
```

## Tips

<table data-view="cards"><tbody>
<tr><td>Infinite Loop Protection</td><td>Always ensure loop conditions will eventually become false. Infinite loops will cause your script to hang and may be terminated by the runtime.</td><td></td></tr>
<tr><td>Variable Scope</td><td>Loop variables like `i` are scoped to the loop. Use `var` declarations inside loops for temporary calculations.</td><td></td></tr>
<tr><td>Performance</td><td>Loops run during the calculation phase of each bar. Keep iterations reasonable to maintain good performance across large datasets.</td><td></td></tr>
<tr><td>Timeseries Restriction</td><td>You cannot declare `timeseries` inside loops. Timeseries must be declared in global scope only.</td><td></td></tr>
</tbody></table>