Game Development
Writing to a file
Learn to write to a file with Application.persistentDataPath.
Safe File Path: persistentDataPath
Across platforms like desktop, iOS, and Android, write permissions do not exist in the installation folder. Unity resolves this by providing Application.persistentDataPath, a dedicated safe write directory for every OS.
using System.IO;
// Cross-platform safe path construction
string path = Path.Combine(Application.persistentDataPath, "save.json");
The Path.Combine method automatically selects the appropriate path separator slash for the target operating system.
Writing to Disk with File.WriteAllText
The most convenient way to write a serialized JSON string to disk is via System.IO.File.WriteAllText. This method creates the file if missing, or overwrites it if it already exists.
using System.IO;
string json = "{\"health\": 100}";
File.WriteAllText(path, json);
Wrapping file writing operations inside try-catch blocks is recommended to catch permission or storage issues.
Exercise Creating save file path
Define a Start method. Inside, declare string dosyaAdi = "save.json"; and print "Kayit dosyasi: " + dosyaAdi to the console.
Show example solution
using UnityEngine;
public class SaveWriter : MonoBehaviour
{
void Start()
{
string dosyaAdi = "save.json";
Debug.Log("Kayit dosyasi: " + dosyaAdi);
}
}
Test yourself
-
Which Unity path should be used to reliably write game save files across various operating systems?
- Application.temporaryCachePath
- Application.persistentDataPath
- Application.dataPath
- Application.streamingAssetsPath
Show answer
Application.persistentDataPath — Application.persistentDataPath is the dedicated path across all platforms reserved for persisting user data safely.
-
Write text to file
File.____(filePath, jsonContent);
Show answer
File.WriteAllText(filePath, jsonContent);
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File writing terms
- persistentDataPath
- Platform-specific safe save directory
- Path.Combine
- Safely joins directory and file name
- File.WriteAllText
- Writes text to a file in one operation
- StreamWriter
- Stream-based file writing class
Next lesson: Reading from a file
