precedence

Simple_Sequential_Calculator.js

//application/javascript
//
// A simple sequential calculator.
// By Andrew Kingdom
// MIT license
//
// Operator order/precedence is ignored.
// The calculation string is expected to have numbers and operators separated by spaces.
//
function operate(x,oper,y) {
	console.log('x:' + x + '  oper:' + oper + '  y:' + y);
	if(oper == '') {
		answer = y;  // no operator -- reset result
  	} else {
		answer = eval(x+oper+y);
  	}
	console.log(' =' + answer);
 	return answer;
 	
}

function calc(str) {
 	tokens = str.split(' ');  // space delimited tokens
 	operator = '';
 	result = 0;

  for(let token of tokens){ 
 	  number = parseFloat(token);
 	  if(!isNaN(number))
  	 	result = operate(result,operator,number);
	  else if('+/*-'.indexOf(token) != -1)
	  	operator = token;
	  else
		return 'invalid token';
 	}
 	return result;
}
console.log(
"The result is: " + calc('2 + 3 + 35 / 68 / 9 * 37 - 8 + 67 + 9'));

/* OUTPUT:

x:0  oper:  y:2
  =2
x:2  oper:+  y:3
  =5
x:5  oper:+  y:35
  =40
x:40  oper:/  y:68
  =0.5882352941176471
x:0.5882352941176471  oper:/  y:9
  =0.06535947712418301
x:0.06535947712418301  oper:*  y:37
  =2.4183006535947715
x:2.4183006535947715  oper:-  y:8
  =-5.5816993464052285
x:-5.5816993464052285  oper:+  y:67
  =61.41830065359477
x:61.41830065359477  oper:+  y:9
  =70.41830065359477
The result is: 70.41830065359477
*/

that's cool man, a lovely tool for maths student like me