Final answer:
The default scope for variables inside of blocks is local to that block, which prevents them from being accessed outside. This is known as block scope.
Step-by-step explanation:
The default scope for variables inside of blocks in most programming languages is local to that block. A variable declared within a block is generally not accessible outside of it. This is known as block scope, which is typical in languages like JavaScript (when using let or const), C++, and Java.
In contrast, languages like Python use function scope for variables, meaning variables are only scoped to the function they are defined in, not necessarily the blocks within.
For example, in JavaScript:
if (true) {
let localVariable = 'I am local to this if block';
console.log(localVariable); // Outputs the value
}
console.log(localVariable); // Uncaught ReferenceError: localVariable is not defined
This demonstrates that the variable localVariable is not accessible outside of the if block.