How do you redeclare variables in a switch block without an error?

When you try to redeclare variables using let or const in multiple case clauses of a switch statement, you will get a SyntaxError. This happens because, in JavaScript, all case clauses within a switch statement share the same block scope. For example:

    let counter = 1;
    switch (x) {
      case 0:
        let name;
        break;
      case 1:
        let name; // SyntaxError: Identifier 'name' has already been declared
        break;
    }
    

To avoid this error, you can create a new block scope within each case clause by wrapping the code in curly braces {}. This way, each let or const declaration is scoped only to that block, and redeclaration errors are avoided:

    let counter = 1;
    switch (x) {
      case 0: {
        let name;
        // code for case 0
        break;
      }
      case 1: {
        let name; // No SyntaxError
        // code for case 1
        break;
      }
    }
    

That means, to safely redeclare variables in different cases of a switch statement, wrap each case’s code in its own block using curly braces. This ensures each variable declaration is scoped to its specific case block.