Function Block passing in TypeScript

Block passing is a TypeScript feature that allows you to capture and pass the variables from the outer scope to inner scope in a single block statement. Here's how to use it:

First, assign your variables in the outer scope:

let firstName = "John";
let lastName = "Doe";
let age = 30;

Then, you can use block passing syntax to pass these variables to an inner scope:

{
  let firstName = "Jane", age = 25;
  // inner scope block code here
}

Note that the variables passed with the inner block will have a higher precedence over the outer-scope variables of the same name.

Here's an example that puts these concepts into practice:

let firstName = "John";
let lastName = "Doe";
let age = 30;
{

  let firstName = "Jane", age = 25;

  console.log(Name: ${firstName} ${lastName}, Age: ${age});

  // output: "Name: Jane Doe, Age: 25"

}
console.log(Name: ${firstName} ${lastName}, Age: ${age});

// output: "Name: John Doe, Age: 30"

In this example, we used block passing to temporarily override the variables firstName and age. When we logged out the values inside the block, we saw that the inner variables were used. However, outside the block, the original values were preserved.