INPUT VALUE TO USE IN IF STATEMENTS IN PHP

Question

How can I use the value received from the user by input box in if .
For example :I received a user input of "Alex"
Now I want to use the Alex in if statement so that the if statement will only execute or echo it is true when the user input is
<?php $value = $_POST["user"];
If($value==Alex){
Echo ("yes");
}
Else {
Echo("no");
}

So is it right ,whenever I run this ok local host it show error of Alex value
Can anyone help me with this
I'm a beginner.

Answer 1

// Write if($value == "Alex")
Because Alex is string so we have to write it between " " or '.' ;
Or

//$username ="Alex" ;
if($value == $username)

Here we already put a value to $username with "Alex"

Answer 2

Whenever you're working with a string in an if statement you should put it inside quotation marks.

Answer 3

Change the if statement to this:
if($value=="Alex")