gistfile1.js

function All() {   
    var doc = app.activeDocument;
    // list of items we might want to loop through
    var itemsToLoop = [doc.layers, doc.symbolItems];
    //reference for method to know how many layers, pathitems, symbols etc are being looped
    //can I do: this.itemsToLoop = [doc.layers, doc.symbolItems]; to remove prev var?
    this.name = itemsToLoop;
}

All.prototype.findAndReplace = function(find, replace) {
    var findTextInSymbolName = prompt("Text to find", find);
    var replaceTextInSymbolName = prompt("Text to replace", replace);

    for( i = 0; i < this.itemsToLoop[i].length; i++){
        for( i = 0; i < this.itemName[i].length; i++){
            // find and replace, if no matches then it just continues with no changes, 
            // built into replace method.
            var currentItemName = itemToLoop[i].name;
            currentItemName.replace(findTextInSymbolName, replaceTextInSymbolName);
         }
    }
}


function SymbolName() {
    this.name = doc.symbolItems;
}

SymbolName.prototype.findAndReplace = function(find, replace) {
      var findTextInSymbolName = prompt("Text to find", this.find);
      var replaceTextInSymbolName = prompt("Text to replace", this.replace);
    
      for( i = 0; i < this.itemsToLoop[i].length; i++){
        for( i = 0; i < this.itemName[i].length; i++){
            // find and replace, if no matches then it just continues with no changes, 
            // built into replace method.
            var currentItemName = itemToLoop[i].name;
            currentItemName.replace(findTextInSymbolName, replaceTextInSymbolName);
         }
    }  
}