Question

1. When programming in the Unix/Linux shell, short-circuit evaluation of an expression is a standard way to execute a second command ONLY IF the first command was successful. How does this work?

2. What is a ternary operator? When should it be used and when should it be avoided?

3. We perform a hand trace of a C program to validate what?

Answer 1

As per your question, First I will describe to you what is short-circuit evaluation of expression next how it is working in Unix/Linux further the ternary operator and its advantages/disadvantages. So, please bear with me:-

The Short-circuit evaluation of an expression is an in-line expression(including the scripts and shell functions we write) that sends an exit code/status whenever execute, if the exit code/status is 0 then the executed expression is succeeded. Otherwise, failure of the expression execution due to some reason. The range of the exit code/status is defined 0 to 255. The Unix/Linux Kernel shell provides a parameter in-order to examine the exit code/status, as shown in below:-

Now coming to the ternary operator,

In the computer programming world, ?: is identified as a ternary operator i.e. part of the syntax for basic conditional expressions in various programming languages. For example, C programming language, C++ programming language, and java programming language.

The basic syntax of the ternary operator is shown below:-

variable = Expression1 ? Expression2 : Expression3

The Flow Chart for above written ternary expression is shown below:-

Advantages of the ternary operator:-

• It is shorter and more concise when dealing with direct value comparisons and assignments.
• It will increase code readability by reducing the number of lines of code.

Disadvantages of the ternary operator:-

• It is restricted or limited up to only two conditional situations.

Example in C programming language(please refer to in-line comments for better understanding and hand trace):-

// Basic C program to find the largest among two numbers using ternary operator 
  
#include <stdio.h> 
// main driver method
int main() 
{ 
    // variable declaration 
    int num1 = 5, num2 = 10, max; 
  
    // Largest among n1 and n2 
    max = (num1 > num2) ? num1 : num2;
    //max = (5 > 10) ? 5 : 10; if (5>10) true then 5 is assigned to max otherwise 10 assigned to max.
    
    // Print the largest number 
    printf("Largest Number: %d", max);
  
    return 0; 
} 

I hope, now you have a brief knowledge about Short-circuit evaluation of an expression and it's working.

And also have a brief knowledge about ternary operators and concept behind it.

Please don't forget to like it...

Thank you...