class stringcalc {
    str: string;
    arr: any[];
    temp: number;
    conversion(str: string) {
        this.str = str;
        this.arr = this.str.split(' ');
        return this.arr;
    }
    calc() {
        for (let i = 0; i < this.arr.length; i++) {
            if (this.arr[i] == '*') {
                this.mul(i);
                i -= 2;
            }
        }
        for (let i = 0; i < this.arr.length; i++) {
            if (this.arr[i] == '/') {
                this.divi(i);
                i -= 2;
            }
        }
        for (let i = 0; i < this.arr.length; i++) {
            if (this.arr[i] == '+') {
                this.sum(i);
                i -= 2;
            }
        }
        for (let i = 0; i < this.arr.length; i++) {
            if (this.arr[i] == '-') {
                this.diff(i);
                i -= 2;
            }
        }
        return this.arr;
    }

        divi(i: number) {
            this.temp = parseFloat(this.arr[i - 1]) / parseFloat(this.arr[i + 1]);
            this.arr[i + 1] = this.temp;
            this.arr.splice(i - 1, 2);
            return this.arr;
        }
        mul(i: number) {
            this.temp = parseFloat(this.arr[i - 1]) * parseFloat(this.arr[i + 1]);
            this.arr[i + 1] = this.temp;
            this.arr.splice(i - 1, 2);
            return this.arr;

        }
        sum(i: number) {
            /*this.arr[i - 1] = typeof this.temp;
            this.arr[i + 1] = typeof this.temp;
            this.arr[i] = typeof this.temp;
            var temp1: number = this.arr[i - 1];
            var temp2: number = this.arr[i + 1];
            this.temp = temp1 + temp2;*/
            this.temp = parseFloat(this.arr[i - 1]) + parseFloat(this.arr[i + 1]);
            this.arr[i + 1] = this.temp;
            this.arr.splice(i - 1, 2);
            return this.arr;

        }
        diff(i: number){
            this.temp = parseFloat(this.arr[i - 1]) - parseFloat(this.arr[i + 1]);
            this.arr[i + 1] = this.temp;
            this.arr.splice(i - 1, 2);
            return this.arr;
        }
    }

/*var ip = new stringcalc();
var arr1: any = ip.calc("10 + 12 / 2 / 3 - 7");
console.log(arr1);*/