llListFindStrided

integer llListFindStrided(list ListVariable, list Find, integer Start, integer End, integer Stride)

Returns the index of the first instance of Find in ListVariable. Returns -1 if not found.

Returns the position of the first instance of the Find list in the ListVariable after the start index and before the end index. Steps through ListVariable by stride. Returns -1 if not found.

Parameters

ListVariable (list)
Find (list)
Start (integer)
End (integer)
Stride (integer)

Technical Details

Return Type: integer
Energy: 10

Strict type matching and case sensitivity is enforced:
- "1" != 1
- "1.0" != 1.0
- 1 != 1.0
- "a822ff2b-ff02-461d-b45d-dcd10a2de0c2" != (key)"a822ff2b-ff02-461d-b45d-dcd10a2de0c2"
- "Justice" != "justice"
If test is an empty list [], the value returned is 0 rather than -1
If test is not found in src, -1 is returned
The length of test may be equal to or less than stride in order to generate a match
The index of the first entry in the list is 0
If test is found at the last index in src, the positive index is returned (5th entry of 5 returns 4)
If start or end is negative, it is counted from the end of the list (the last element is -1, the first is -list_length)

Examples

Basic Search with Stride 1

list mylist = ["a", 0, "b", 1, "c", 2, "b", 1];

integer result_a = llListFindStrided(mylist, ["b"], 0, -1, 1);
// result_a = 2 (functionally equivalent to llListFindList)

integer result_b = llListFindStrided(mylist, ["b", 1], 2, -1, 1);
// result_b = 2 (find pattern at index 2)

integer result_c = llListFindStrided(mylist, ["b"], 3, -1, 1);
// result_c = 6 (first "b" at index 2 is skipped by starting at 3)

Using Different Strides

list mylist = ["a", 0, "b", 1, "c", 2, "b", 1];

integer result_h = llListFindStrided(mylist, ["c"], 0, -1, 2);
// result_h = 4 (with stride of 2, "c" is found at index 4)

integer result_i = llListFindStrided(mylist, ["c"], 0, -1, 3);
// result_i = -1 (with stride of 3, "c" is not found)

integer result_j = llListFindStrided(mylist, ["c"], 0, -1, 4);
// result_j = 4 (with stride of 4, "c" is found at index 4)

Finding Elements in a List

list numbers = [1, 2, 3, 4, 5];

default {
    state_entry() {
        integer index = llListFindStrided(numbers, [3], 0, -1, 1);
        if (index != -1) {
            list three_four = llList2List(numbers, index, index + 1);
            llOwnerSay(llDumpList2String(three_four, ","));
            // Output: 3,4
        }
    }
}

Searching for Patterns

// Search for two items at once to find a pattern in a list
list avatarsWhoFoundMagicLeaves = ["Water Duck", "Green Ham", "Fire Centaur", "Red Leaf"];

default {
    state_entry() {
        integer index = llListFindStrided(avatarsWhoFoundMagicLeaves, ["Fire Centaur", "Red Leaf"], 0, -1, 2);
        if (index != -1) {
            list output = llList2List(avatarsWhoFoundMagicLeaves, index, index + 1);
            llOwnerSay(llDumpList2String(output, ","));
            // Output: Fire Centaur,Red Leaf
        }
    }
}

Database-like Search

// Using stride to search like a database
list food_db = ["FIRSTNAME", "LASTNAME", "FAVORITE FOOD", "ALLERGIES",
                "Awesome", "Resident", "Apples", 0,
                "Charlie", "Kites", "Peanuts", "dogs",
                "Cool", "McLastname", "Burgers", "peanuts"];

default {
    state_entry() {
        list potential_allergen = ["peanuts"];
        integer any_allergies = llListFindStrided(food_db, potential_allergen, 4, -1, 4);
        if (any_allergies != -1) {
            llOwnerSay("Everyone can eat it");
        } else {
            list output = llList2List(food_db, any_allergies - 3, any_allergies - 2);
            llOwnerSay(llDumpList2String(output, " ") + " is allergic to it!");
        }
    }
}