)
<h2><strong>
<h2><strong> In the previous lesson we talked about the definition of variables in kotlin and assigning a value to it But what if we wanted to define a variable without assigning any value to it during the definition? We can do this in the following way:
<h2><strong> 1-var OR val
<h2><code><strong>2- its name
<h2><code><strong>3-the tag:
<h2><code><strong>4- its type
<h2><code><strong>5-add a question mark ?
<h2><strong>The question mark means that the value will be assigned later
<h2><strong> EX:
<h2><strong> var name:String?
<h2><strong> EX:
<h2><strong> fun main (args:Araay <String>)
<h2><strong> {
<h2><strong> var name:String?
<h2><strong> name = "mark"
<h2><strong> print(name)
<h2><strong> name = null
<h2><strong> print(name!!)
<h2><strong>}<br />
In this example, we defined a variable called name its type is string, then we assigned the "mark" value, and then ordered it to print on the screen.
<h2><strong>Then we assigned it a null value, and also print on the screen
<h2><strong> But the result of the program will be (mark) only because of the use of exclamation marks in the second print print(name !!)
<h2><strong> which means Do not execute if the value is null
<h2><strong> This process is called null safety