title: Convert String to operator(+*/-) in java
body: <p>I am using Stack class to calculate simple arithmetic expressions involving integers,
  such as 1+2*3.your program would execute operations in the order given,without regarding to the precedence of operators.
  *Thus, the expression 1+2*3 should be calculated (1+2)*3=9,not 1+(2*3)=7.</p>
  
  <p>If i get the input as 1+2*3,i know how to convert the string 1,2,3 to Integer.but i don't know how to covert +,* from string type to operator.</p>
  
  <p>My code logic is:
  For eg: Given string 2 + (3 * 5), So 3 * 5 will be operated first then +2 will be performed in result of 3 * 5.</p>