AngularJS forEach并添加值

Question

var grandTotal;
angular.forEach($scope.gear, function(value, key) {
    var rowTotal = value.amount * value.price;
    console.log(rowTotal);
    grandTotal += rowTotal; 
});
console.log('grandTotal: '+grandTotal);

我有上述内容，我正在尝试获得赠款总额，似乎为我的grandTotal

返回NaN

更新：

var grandTotal = 0;
angular.forEach($scope.gear, function(value, key) {
    var rowTotal = value.amount * value.price;
    rowTotal = rowTotal.toFixed(1);
    console.log(rowTotal);
    grandTotal += rowTotal;
});
console.log('grandTotal: '+parseFloat(grandTotal));

这将返回

Answer 1

如何使用vanilla javascript map和reduce函数？

基于您的目的的例子：http://jsfiddle.net/optyler/G2ZJa/