i did it too ,but

[johny doe]

there are lots of stuff that executes parsing
but i codnt find

a fuction wich

for example takes (1+i) as a string
and converts it to a complex type variable

[Ernest Friedman-Hill]

There's no such function in Java. The Java APIs do not contain any kind of expression parser. Writing a program which evaluates math expressions like this will be one of the first examples in any book on writing compilers; otherwise, you can use an existing library like BeanShell.

[Jim Yingst]

Continued from https://coderanch.com/t/384189/java/java/String-recognition-questions