rpn calculator CLI tool in js

rpn_calc.js

// This function would be used for the CLI program for a RPN calculator
// This assumes that variable stdout is the last value that was stored by the CLI

var rpn_calc = (inputs) => {
	const stack = [];

    // pseudocode: check the last value for stdout
    // stdout is the last stored value in standard out
    if (typeof parseInt(stdout) === 'number' ) {
        stack.push(parseInt(stdout)) 
    }

	// split the input into an array
    const inputsArr = inputs.trim().split(' ')
    
	inputsArr.forEach( input => {
		switch (input) {
			case '+':
				stack.push(stack.pop() + stack.pop());
				break
			case '-':
				stack.push(-stack.pop() + stack.pop());
				break;
			case '*':
				stack.push(stack.pop() * stack.pop());
				break;
			case '/':
				stack.push((1 / stack.pop() * stack.pop()));
				break;
			default: 
				stack.push(parseInt(input));
				break;
		}
	});

    // return last item in the stack
    if (parseInt(stack[stack.length - 1]) === 'NaN') {
        return 'Error'
    } else {
        return stack[stack.length - 1];
    }
}