Uses of the finally statement

Question

This is a very basic question. In Java I use the finally statement to close resources because "it's a good practice". I've been developing in Javascript and then in Node.js during some years and I've never used the finally statement. I know that in Node.js all of us follow the first parameter error handling pattern. Anyway, the 2 following snippets do the same:

try{     throw 123 }catch (e){  }finally{     console.log(1) } 

.

try{     throw 123 }catch (e){  }  console.log(1) 

Both print 1.

Why is finally a keyword if it has no real benefit? The clean up code can be put inside the catch.

Answer 1

finally is useful for more than just exception handling — it allows the programmer to avoid having cleanup code accidentally bypassed by a return, continue, or break.

Just a simple and straightforward example that shows the difference. There is a return that breaks the function completion, but the console.log in finally is called while the last console.log is skipped.

let letsTry = () => {      try {      // there is a SyntaxError      eval('alert("Hello world)');          } catch(error) {      console.error(error);  	      // break the function completion      return;    } finally {        console.log('finally')    }      // This line will never get executed    console.log('after try catch')  }    letsTry();