sheetworker populate repeating element from array of objects

I have a fieldset named repeating_weap which I am trying to populate from a dropdown selection. This is a simplified version of the sheet worker, but I am trying to populate values in the repeating section from an array of objects. The code runs, but the values in the repeating section all end up as "undefined". I think I'm close to implementing this correctly, but I'm not sure what I'm missing.  on("change:thetype sheet:opened", function() {     getAttrs(["thetype"], function(values) {   let dsply = values.thetype; let A =  {name:"1", type:"melee", weapons:[ {name:"Dagger", damage:"1-4"}, {name:"Sword", damage:"1-8"}] }; let B =  {name:"2", type:"archer", weapons:[ {name:"Short Bow", damage:"1-6"}, {name:"Long Bow", damage:"1-8"}, {name:"Crossbow", damage:"1-8"}]  }; let charinfo = [A,B];         for (i = 0 ; i < charinfo.length ; i++) {             if (charinfo[i].name == dsply) {                 setAttrs({['type']: String(charinfo[i].type)}); const settings = {};  //create an object to store the new rows for (a in charinfo[i].weapons) { const newrowid = generateRowID();     settings["repeating_weap_" + newrowid + "_weaponname"] = String(a.name);     settings["repeating_weap_" + newrowid + "_weapondamage"] = String(a.damage); } setAttrs(settings);             }         }     }); });

You've actually got the weapons stored as an Array, so you're better off using a forEach loop there (the for...in loops is intended for key:value pairs in an object). You can also make it a little more efficient by storing everything in the 'settings' object you declared and just running setAttrs once - I don't write sheets, but my understanding it that minimising the use of getAttrs and setAttrs makes the sheet more responsive. I had to take some stuff out to run it in node, hopefully I put it back together properly: on("change:thetype sheet:opened", function () { getAttrs(["thetype"], function(values) { let dsply = values.thetype; let A = { name: "1", type: "melee", weapons: [{ name: "Dagger", damage: "1-4" }, { name: "Sword", damage: "1-8" }] }; let B = { name: "2", type: "archer", weapons: [{ name: "Short Bow", damage: "1-6" }, { name: "Long Bow", damage: "1-8" }, { name: "Crossbow", damage: "1-8" }] }; let charinfo = [A, B]; for (let i = 0; i < charinfo.length; i++) { if (charinfo[i].name == dsply) { let settings = {} //create an object to store the new rows settings['type'] = charinfo[i].type charinfo[i].weapons.forEach(weap => { let newrowid = generateRowID(); settings["repeating_weap_" + newrowid + "_weaponname"] = weap.name; settings["repeating_weap_" + newrowid + "_weapondamage"] = weap.damage; }) setAttrs(settings) } } }); }); The setAttrs should probably go outside the for() loop to ensure it only runs once, with a full object.... but I'm assuming it's impossible to have more than 1 match for charinfo[i].name == dsply, so it isn't a big deal here.

Thanks, that did it. I had tried doing something with a for loop like this:  for (let a = 0; a < charinfo[i].weapons.length; a++) but was still having trouble with the values being undefined. You're method of looping worked perfectly!