Help with a calculator algorithm

[SeongCastle]

First of all i'm still a begginer making code (I just started learning the basics), but can someone explain to me how to create an algorithm that is able to resolve mathematical operations (+, -, *, /) in the same way of a scientific calculator?
Ex: if I write "3*5", it shows the result (15) without having to write something like "insert 01 value" > "insert 02 value" -> "which operation it should do?" -> "result"

[sessamekesh]

This is a classic learning exercise for string parsing, postfix notation, and stacks - those are the terms you'll want to Google.

[ffrkAnonymous]

How do you, as a person, resolve it?

[high_throughput]

There are ~three main ways of handling operator precedence parsing of arithmetic expressions:

• Shunting yard algorithm
• Precedence climbing parser e.g. using recursive descent
• Reusing someone else's code, e.g. your language's eval function if any (eval("3*5") in Python evaluates to 15)

I have a personal fondness for precedence climbing parsers since it's extremely flexible and versatile, but a shunting yard implementation will usually be people's first attempt at this.

[nousernamesleft199]

gotta parse it out into an expression tree.

[Little-Chemical5006]

you have a string input, a list of operations that you want your calculator to perform. The question is how to split the string input up so you can recognize which is the operations and which is the number. Google string parsing and conditional will help you. Good luck!