Iterate through Generic List

[Story_Specialist]

Hey all,

I’m working on a little project to practice both my narrative design skills, as well as my Unity basics. Without explaining the entire thing, I can say that what I want is for the player to be able to collects phrases (Strings) to form a piece of text. Eventually, I want them to be able to remove or rearrange the phrases as well, but I’m taking it one step at a time.

After doing a bit of research, I figured using a Generic List was best. What I want to do is this: add items (Strings) to the List, then iterate through that List and spawn a GUI.Button for each item in the List (each button having its own space).

I came up with this (I work in Javascript):

import System.Collections.Generic;

var phraseList = new List.<String>();

function OnGUI () {

		phraseList.ForEach (
			function() {
				if (GUI.Button (Rect (100, 20 * phraseList.Item, 200, 20), "button")) {
					Debug.Log ("Box #" + phraseList.Item + " is working");
				}
			}
		);
		
}

function Update () {
	if (Input.GetKeyUp ("z")) {
		phraseList.Add("Test string 1");
		phraseList.Add("Test string 2");
		phraseList.Add("Test string 3");
		phraseList.ForEach (print);
		
	}
}

But I get the following error message: “The property ‘System.Collections.Generic.List.Item’ cannot be used without parameters.”

What kind of property do I need for “the current item”, if you will? I hope you guys can help a beginner out!

Thanks in advance,

Veliremus

[Story_Specialist]

After receiving two answers by @syclamoth and @Erich5h5, I managed to get the generic List working in Javascript.

Javascript (solution provided by Eric5h5):

---

import System.Collections.Generic;

var phraseList = new List.<String>();

function OnGUI () {
	
	var i : int = 0;
	for (str in phraseList) {
		if (GUI.Button (Rect (100, 20 * i, 200, 20), str)) {
			Debug.Log ("Box #" + i + " is working!");
		}
	i++;
	}

}
	
function Update () {
	if (Input.GetKeyUp ("z")) {
		phraseList.Add("Test string 1");
		phraseList.Add("Test string 2");
		phraseList.Add("Test string 3");
		
	}

}

---

C# (solution provided by syclamoth):

---

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class Bluh : MonoBehaviour {

List<String> phraseList = new List<String>();

void OnGUI() {
    int i = 0;
    foreach(String str in phraseList)
    {
       if(GUI.Button (Rect (100, 20 * i, 200, 20), str)) {
         Debug.Log("Box #" + i + " is working");
       }
       i++;
    }
}
void Update () {
    if(Input.GetKeyUp("z"))
    {
       phraseList.Add("Test string 1");
       phraseList.Add("Test string 2");
       phraseList.Add("Test string 3");
       foreach(String str in phraseList)
       {
         Debug.Log(str);
       }
    }
}
}

---

Thank you both very much!

[syclamoth]

You’re on the right track here, but I don’t quite know if the syntax is right. Personally, I work in C# exclusively (I find javascript just unendingly frustrating because it lacks this kind of functionality)- As far as I can tell, Javascript does not support generic lists the way you want them. I would recommend porting your script to C#- it doesn’t take very long, and learning to program in it will be worthwhile in the long-term as well. For the script you posted there, the translation would be somthing along the lines of:

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class Bluh : MonoBehaviour {

List<String> phraseList = new List<String>();

void OnGUI() {
	int i = 0;
	foreach(String str in phraseList)
	{
		if(GUI.Button (Rect (100, 20 * i, 200, 20), str)) {
			Debug.Log("Box #" + i + " is working");
		}
		i++;
	}
}
void Update () {
	if(Input.GetKeyUp("z"))
	{
		phraseList.Add("Test string 1");
		phraseList.Add("Test string 2");
		phraseList.Add("Test string 3");
		foreach(String str in phraseList)
		{
			Debug.Log(str);
		}
	}
}
}