 Hi everyone! In this video, we're going to talk about mutable and immutable variables in Rust language. But first of all, make sure to subscribe to my channel. More subscribers means more quality videos on my channel. So in the comments section, you can put a comment or link on anything related with Rust language or programming in general. Okay, let's back to the topic. Suppose that we have a variable and someone wants to change this variable somehow, somewhere and maybe that can produce a bug in our code. We don't want to make some of our variables to be so easy to change their values. So to prevent this in Rust, we can use immutable variables. That means that we can't change its value during code execution. All variables in Rust are by default immutable. So let's make a variable. This variable is going to be immutable by default. So let's make a variable my variable and let's say that it has value 5. Okay, let's print our variable. We will get number 5 as printed result. But what will happen if we want to change this immutable variable? For example, let's try to say that my variable now is 6 and let's try to run it. We're gonna get an error which said that we cannot make new assignment of our immutable variable my variable. Our variable is immutable. We can't change its value. But if we want to change value of our variable, first we need to make it mutable. And we're going to do that by using mut keyword and now we can change our variable. Okay, let's run this code again and now we can change this variable, but we're gonna get a warning. We're gonna get warnings all the time in Rust language. That's good because we will not have big number of bugs in our code. So this warning is tell us that value of my variable, which is 5, is never read. So we can use this value of 5, for example here by calling this my variable, which has value of 5 and add, for example, number 3 to it and let's run this code again. And now we will get result number 8. So all variables in Rust language are immutable. That means that you can change their values during code execution. But if you want to change their values, you need to use keyword mute to define that your variable can be changed. That's all for now. Don't forget to subscribe to my channel. See you in the next video. Bye.