Angular 4 - 數組之和

Question

ng4/typescript 的新手並且有一些困難。 如何對數組中的項目求和？

添加 例如，它在行動中的樣子的屏幕截圖

        for (let card of this.cards) {
              for (let val of card.cards){
                if(val.value == "JACK"){
                  val.value = 10;
                }
                if (val.value == "QUEEN"){
                  val.value = 10;
                }
                if (val.value == "KING"){
                  val.value = 10;
                }
                if (val.value == "ACE"){
                  val.value = 10;
                }

                this.hand = Number(val.value) + Number(val.value); (I'm sure this is wrong)

             }
          }

Answer 1

使用Array#Reduce ：

 // Array of numbers var array = [1,2,3,4,5]; var sum = array.reduce((acc, cur) => acc + cur, 0); console.log(sum) // Array of strings var toNumber = ['1','2','3','4','5']; var sumNumber = toNumber.reduce((acc, cur) => acc + Number(cur), 0) console.log(sumNumber);

Answer 2

let sum = array.reduce(function (acc, cur) { return acc + cur; });