What is a local block? Ans. A local block is any portion of a C program that is enclosed by the left brace ({) and the right brace (}). A C function contains left and right braces, and therefore anything between the two braces is contained in a local block. An if statement or a switch statement can also contain braces, so the portion of code between these two braces would be considered a local block. Additionally, you might want to create your own local block without the aid of a C function or keyword construct. This is perfectly legal. Variables can be declared within local blocks, but they must be declared only at the beginning of a local block. Variables declared in this manner are visible only within the local block. Duplicate variable names declared within a local block take precedence over variables with the same name declared outside the local block. Here is an example of a program that uses local blocks: #include void main(void); void main() { /* Begin local block for function main() */ int test_var = 10; printf('Test variable before the if statement: %d\n', test_var); if (test_var > 5) { /* Begin local block for 'if' statement */ int test_var = 5; printf('Test variable within the if statement: %d\n', test_var); { /* Begin independent local block (not tied to any function or keyword) */ int test_var = 0; printf( 'Test variable within the independent local block:%d\n', test_var); } /* End independent local block */ } /* End local block for 'if' statement */ printf('Test variable after the if statement: %d\n', test_var); } /* End local block for function main() */ This example program produces the following output: Test variable before the if statement: 10 Test variable within the if statement: 5 Test variable within the independent local block: 0 Test variable after the if statement: 10 Notice that as each test_var was defined, it took precedence over the previously defined test_var. Also notice that when the if statement local block had ended, the program had reentered the scope of the original test_var, and its value was 10.

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