in javascript: Calculator

Create a function per the following requirements:

Input

Ask the user for the following

$$ Number$1$

$$ Number$2$

$$ Mathematical Operation $(+,-,*,/)$

Assume valid input

Return

The result of the mathematical operation in the following format:

Number$1$ operation Number$2=$ result.

Examples:

Input $($can use multiple prompts$)$: $1,2,+$

Output $($note the format$)$: $1+2=3$

Input: $12,3,/$

Output: $12/3=4$in javascript :