Javascript比较和合并新数组中的项目

Question

I'm trying to take an array list and combine like objects into a new array, but I keep coming up short of what I'm trying to do. Note: I am using jQuery $.each() among other things that might make this 'slower' but I just want the logic to work first.

So, short story: I have items that a user can select, When they select an item, I put it into an array list called materials . This array list houses everything the user has selected and all of the item's sub-items. here's and example: If the user selects "Wood Barricade" and "Sleeping Bag" it will add to the materials array and output like so:

["woodBarricade|1", "wood|30", "sleepingBag|1", "cloth|15"];

Now, if the user adds in "Wood Planks", the array becomes:

["woodBarricade|1", "wood|30", "sleepingBag|1", "cloth|15", "woodPlanks|1", "wood|10"];

What I am trying to do now is combine like selections. In the example above, It should combine the two "wood" items and the new array should say:

["woodBarricade|1", "wood|40", "sleepingBag|1", "cloth|15", "woodPlanks|1"];

Here's what I have so far:

function calculateMaterials(){ //Start the function
    var conMaterialList = []; //Empty the list every time.
    $.each(materials, function(a){ //for each material in the list
        var materialName = materials[a].split("|")[0]; //Get it's name
        var materialCount = parseInt(materials[a].split("|")[1]);  //And the quantity
        if(conMaterialList == ""){  //Then if the conMaterialList is empty
            conMaterialList.push(materialName+"|"+materialCount); //Add the first material
        } else {  // If the conMaterialList is NOT empty
            $.each(conMaterialList, function(b){ //iterate through the list
                var materialNameComp = conMaterialList[b].split("|")[0]; //Get the name
                var materialCountComp = parseInt(conMaterialList[b].split("|")[1]); //Get the quantity
                if(materialName == materialNameComp){ // If the item from 'materials' matches an item from 'conMaterialList'
                    conMaterialList.splice(b, 1, materialNameComp +"|"+ parseInt(materialCount + materialCountComp)); //combine that material
                } else {  // If it does not match
                    conMaterialList.push(materialName +"|"+ materialCount); //push that material into the array
                }
            });
        }
    });
    console.log(conMaterialList); //Show me the conMaterialList
}

This ALMOST works. If I were to try this with the example above (Select Wood barricade, sleeping bag and wood plank) I would get this as the output:

["woodBarricade|1", "wood|40", "sleepingBag|1", "sleepingBag|1", "cloth|15", "cloth|15", "cloth|15", "cloth|15", "woodPlanks|1", "woodPlanks|1", "woodPlanks|1", "woodPlanks|1", "woodPlanks|1", "woodPlanks|1", "woodPlanks|1", "woodPlanks|1", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10", "wood|10"]

As you can see, the first "wood" has a quantity of 40. This technically did Add the two wood piles together. But what happened after that is a mystery to me at the moment.

I've already been told that I'm doing this the slowest way possible, but I would like the logic to work first before I speed it up.

Any ideas on how to combine items and make a single, succinct list?

Answer 1

I tried to keep the code close to your logic, but using object instead of array.

function calculateMaterials(){ //Start the function
    var conMaterialList = {}; //Start with the blank object.
    $.each(materials, function(materialName, quantity){ //for each material in the obj
        if (materialName in conMaterialList) { // Material exists
            comMaterialList[materialName] += quantity;  // add quantity
        }
        else {  // Material not there
            comMaterialList[materialName] = quantity;   // add material with quantity
        }
     });
    console.log(conMaterialList); //Show me the conMaterialList
}