尝试将百分比加在一起并键入转换

Question

我有一个数字变量。我正在尝试遍历项目并将该对象的值添加到我的变量中以获得总计。数字是百分比并以字符串形式返回（对象中的数字）。

//ADD ALL SUBTASK COMPLETION % AND DIVIDE IT BY TOTAL SUBTASK COUNT
console.log(curItemPercent); //this is hardcoded as 0.8 for now
var total = curItemPercent;
var parentCompletion;

function getTotal(data){
    var index = data.length;
        for(var i = 0; i < index; i++){
            var sum = total + parseInt(data[i].percentage,10);
        }
        taskCount = index+1;
        parentCompletion = total/taskCount;

        console.log('total:' + total);
        console.log('Count: '+ taskCount);
        console.log('percent: '+parentCompletion);
}

我一直都是0，或者数字不添加，总数保持不变。