addOperation.txt

He pushed her roughly out of the way.
addOperation(value){


        if (!this.isOperation(value)) {
            if (!isNaN(this.getLastOperation())) {            
                let lastNumber = this._operations.pop(); 
                let currentNumber = parseInt(lastNumber+value);               
                this._operations.push(currentNumber);
                this.displayResult = currentNumber;
            } else {
                let currentNumber = parseInt(value);
                this._operations.push(currentNumber);
                this.displayResult = currentNumber;
            }     
        } else {
            if (this._operations.length >= 3){
                this.calc();
            } else if(this.isOperation(this.getLastOperation())) {
                this.setOperator(value);
            } else {
                this._operations.push(value); 
            }                                             
        }
    }