# Work with text, numbers and logic nodes > A guided map of Nodespell's data and logic nodes for text, numbers, arrays, objects and JSON, math, conditions and loops, with worked examples. Source: https://docs.nodespell.com/graph/data-and-logic/ · Last updated: 2026-11-10 Data and logic nodes in Nodespell work with values instead of media: text, numbers, true/false values, lists (arrays) and key-value objects. Use them to build prompts from parts, calculate parameter values, choose between inputs, and repeat work for every item in a list. They run in your browser and never use [credits](https://docs.nodespell.com/account/plans-and-credits/). Add any of them with the [Tab menu](https://docs.nodespell.com/graph/add-nodes/) by typing the label shown below, or browse them in the [Node Browser](https://docs.nodespell.com/graph/add-nodes/). The output of a data node connects to any compatible input or [parameter](https://docs.nodespell.com/graph/parameters/), including a model's prompt. ## Text nodes | Node | Use it to | | ------------------------------------------------------------ | -------------------------------------------------------------------------------------------- | | **String Template** | Fill a template such as `A photo of ${0} at ${1}` with the strings connected to **Strings**. | | **String Concat** | Join several strings, with an optional **Prefix**, **Separator** and **Suffix**. | | **String Replace** | Replace text; wrap the search in `/…/` to use a regular expression. | | **String Split** | Split text into an array at a **Separator**. | | **String Case** | Change case, for example **Upper Case**, **Sentence Case** or **Kebab Case**. | | **String Trim**, **String Pad**, **String Slice** | Clean up, pad or cut text. | | **String Length**, **String Includes**, **String Ends With** | Measure or test text. | ## Number and math nodes | Node | Use it to | | ----------------------------------------------------------------------------- | -------------------------------------------------------------------- | | **Plus**, **Minus**, **Multiply**, **Divide**, **Remainder**, **Exponent** | Basic arithmetic on **First** and **Second**. | | **Remap** | Map a value from one range to another, for example 0–1 to 0–100. | | **Clamp** | Keep a value between **Min** and **Max**. | | **Round**, **Floor**, **Ceiling**, **Truncate** | Turn a number into a whole number. | | **Random** | Return a number between 0 and 1; set **Seed** to make it repeatable. | | **Noise** | Return a smooth noise value between 0 and 1. | | **Minimum**, **Maximum**, **Absolute**, **Negate**, **Sign**, **Square Root** | Other common operations. | | **Is Finite**, **Is Integer**, **Is NaN** | Test a number. | ## List (array) nodes | Node | Use it to | | ------------------------------------------------------------------------------------- | ------------------------------------------------------------ | | **Merge As Array** | Collect several values into one array. | | **Array Get Element** | Read one item by index (0 is the first). | | **Array Length** | Count the items. | | **Array Range** | Make a sequence of numbers, such as 0 to 10 in steps of 0.5. | | **Array Slice**, **Array Take** | Keep part of an array. | | **Array Filter**, **Array Deduplicate** | Remove empty, unwanted or repeated items. | | **Array Sort**, **Array Reverse**, **Array Shuffle** | Reorder items; **Array Shuffle** accepts a seed. | | **Array Append**, **Array Insert Item**, **Array Remove Item**, **Array Set Element** | Edit items. | | **Array Concat**, **Array Flatten**, **Array Chunk**, **Array Zip**, **Repeat** | Combine, flatten, split or repeat arrays. | ## Object and JSON nodes | Node | Use it to | | ----------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------- | | **JSON Parse** | Turn JSON text, such as a text model's structured answer, into an object. | | **JSON Stringify** | Turn an object back into text. | | **Object Get Key** | Read one value by its key. | | **Create Object**, **Key Value Pair** | Build an object. | | **Object Add Key**, **Object Delete Key**, **Object Rename Key**, **Object Merge**, **Object Filter** | Edit an object. | | **Object Entries**, **Object From Entries**, **Array Zip Object** | Convert between objects and arrays. | ## Logic, flow control and conversion nodes | Node | Use it to | | --------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ | | **If Else** | Output **True Value** or **False Value** depending on **Condition**. | | **Compare** | Compare two numbers with **Equal**, **Less Than**, **Greater Than** and similar operations. | | **String Compare** | Compare two strings, optionally ignoring case or whitespace. | | **Gate** | Combine two true/false values with **AND**, **OR**, **XOR**, **NOT** and others. | | **Switch Input** | Pass through one of several connected inputs, chosen by its index in **Which** (0 is the first). | | **Is Falsy**, **Is Nullish** | Test whether a value is empty or missing. | | **Map Container** | Run the nodes inside it once for every item in an array. | | **String To Float**, **String To Int**, **To String**, **To Fixed**, **To Precision**, **To Exponential** | Convert between text and numbers. | | **Constant** | Hold a fixed **String**, **Number** or **Boolean** value. | | **Reference** | Read another node's output without a connection. | | **Type Of** | Report the type of a value. | | **Dot**, **No Operation** | Pass a value through unchanged to tidy connections. | ## Example: build a prompt from a template 1. Add two **Constant** nodes with **Value Type** set to **String**, for example `a red bicycle` and `golden hour`. 2. Add a **String Template** node and set **Template String** to `Product photo of ${0}, lit at ${1}`. 3. Connect both constants to its **Strings** input, in order. The first connection fills `${0}`, the second `${1}`. 4. Connect the template's **Value** output to the prompt input of an image model and run it. Change either constant and run again to try a new subject or light without retyping the prompt. For writing longer prompts by hand, see [Prompts and saved text](https://docs.nodespell.com/graph/prompts-and-saved-text/). ## Example: repeat work for every item in a list 1. Add a **Constant** with the text `cat, dog, fox` and connect it to a **String Split** node with **Separator** set to `, `. 2. Add a **Map Container** and connect the split **Output** to its **Items** input. 3. Select the Map Container and press `Enter` to go inside. 4. Add a **Map Item** node (the current item), connect it to a **String Case** node set to **Upper Case**, and connect that to a **Map Output** node. 5. Press `U` to go back out, select the Map Container, and run it. The **Values** output returns the results in the original order: `CAT`, `DOG`, `FOX`. Inside the container, **Map Index** gives the item's position and **Map Length** the total. **Max Concurrency** (default 4, up to 16) sets how many items run at once. Right-click the container and choose **Inspect Map Runs** to see each item's result. > **Note:** Run the Map Container itself. Running a node inside it on its own shows **Run Map body node directly?**, because a direct run does not update the Map's output. ## Example: choose between two values 1. Connect a number, such as a **Random** node with a seed, to **Left** on a **Compare** node. Set **Right** to `0.5` and **Operation** to **Greater Than**. 2. Connect the **Compare** output to **Condition** on an **If Else** node. 3. Connect two prompts, one to **True Value** and one to **False Value**, and use the **If Else** output downstream. For a fixed choice from several options, use **Switch Input** and set **Which** instead. ## Example: read a field from JSON Connect a text model's output that contains JSON to **JSON Parse**, then connect the parsed object to **Object Get Key** and set **Key**, for example `title`. The output is that field's value, ready to use in a **String Template** or as a parameter. ## Frequently asked questions ### Do data and logic nodes cost credits? No. They calculate in your browser and appear in run plans as free updates. ### How do I insert values into a prompt? Use **String Template** with `${0}`, `${1}` and so on in **Template String**, and connect the values to **Strings** in order. You can also write [expressions](https://docs.nodespell.com/graph/expressions/) directly in parameters. ### How do I loop over a list in Nodespell? Put the work inside a **Map Container**, use **Map Item** for the current item and **Map Output** for each result, and connect your array to **Items**. ### What is the difference between Constant and a typed parameter? A **Constant** is a node whose output you can connect to many inputs, so one value can drive several nodes. A parameter value belongs to a single node. ## Related - [Expressions](https://docs.nodespell.com/graph/expressions/): calculate parameter values inline - [Connections](https://docs.nodespell.com/graph/connections/): which outputs fit which inputs - [Levels and Folders](https://docs.nodespell.com/graph/levels-and-folders/): going inside nodes with `Enter` and `U` - [Prompts and saved text](https://docs.nodespell.com/graph/prompts-and-saved-text/): the Prompt node