What is variable Substitution?
Variable substitution is a feature provided by programming and scripting languages that allows the replacement of variables with values at runtime execution.
For example, in a general scenario, you might have pseudocode that stores variable values and computes the addition of two variables during execution, printing the result to the console.
Below is a pseudocode example for understanding purposes.
first = 1
second = 2
result = first + second
print(second)
In the above example, there are two variables (first and second) that contain values (1 and 2). When the code runs, the runtime tool substitutes the variable values (1 and 2), performs the addition (first + second), and prints the result to the console.
Here, the variables are declared for example purposes. In real-time scenarios, variables may hold command-line arguments or settings files that contain dynamic values read at runtime.
Variable substitution is a basic feature provided to enable flexible and dynamic values to be passed at runtime.
Batch Variable Substitution
Batch scripting provides variable substitution that allows to substitues the varlaibe with a value when script is run
@echo off
set msg=welcome to blog
echo Hello, %msg%.
variable declared and assign with a string, During batch script running, the varialble is replaced with value and printed to console