I'm reading input from a user which will consist of all digits. I will read these digits into an integer array and then intersparse them with operators such as + and -. My question is, after I do this, how do I evaluate this expression to an integer? I.E. I read in >>>>> "123456", then I manipulate the integer array to >>>>> "12+3456" Now, what do I do to evaluate that array so that it is the integer 3468?

Just parse the array in a loop making the loop counter to be multiple of 10. Code: // Loops get you one number int temp; for(int i=1,j=0;;i*=10,j++) { if(arr[j] == "Digit") temp += arr[j]*i; else break; } Then get the symbol and then second number and operate on the number depending on the symbol.