num[];//为这个数组;    
arrayValue() {
      for (var j = 0; j <= this.num.length - 1; j++) {
        for (var i = this.num.length - 2 - j; i >= 0; i--) {
          this.num[j] = this.num[j] * 10;
        }
        this.numValue = this.numValue + this.num[j];
      }
      //以上是把每次输入的数字加入到数组,然后算他们的值;
}

以上是【1,2,3,4,5】转成 12345 的方法。

 

接下来讲的是:【1,2,‘.’,3,4】转成12.34的方法

dotBefore;//整数部分
dotAfter;//小数部分 
hasDotArray() {
      this.numValue = 0;
      this.num.forEach(i => {
        if (this.num[i] == '.') {
          this.k = i;
        }
      });
      //先找到小数点的位置k
      var l = this.k - 1;
      var m = 1;
      for (var j = 0; j <= this.num.length - 1; j++) {
        //先计算点之前的和
        if (j < this.k) {
          for (var n = l; n > 0; n--) {
            this.num[j] = this.num[j] * 10;
          }
          this.dotBefore = this.dotBefore + this.num[j];
          l = l - 1;
        }
        //再计算点之后的和
        if (j > this.k) {
          for (var o = m; o >0; o--) {
            this.num[j] = this.num[j]/ 10;
          }
          this.dotAfter = this.dotAfter + this.num[j];
          m = m + 1;
        }
      }
      this.numValue = this.dotBefore + this.dotAfter;
    }