Hi, in this video clip, let me explain a "Input function" and also a way of changing data types. Here's input function, here's the input function. Within input function, you write a sentence, asking people to react to your input function. So in this case, what is your name? Then probably people react to that question. Like "Young Sun". Then, that typed information is assigned to variable name, "your_name". So "your_name" will have the text information a person provided. So, in this case, let me show you, how does it work. So, this one, what is your name? So, input function, you typed this text information? It is typed. Then I react. My name is YoungSun. Then print, print function used in the second line. And "your_name" value contained in "your_name" is return, "YoungSun". So "your_age", another use of input function. "your_age" will take the age, the value, you typed in. How old are you? What about 45? I give "45", then "45". Print "your_age". My age "45" that I provided is printed. And this data type is string. This means that input function takes any value. But they are turn into String. So, the string value is returned from input function. So, remember input function returns string values. But obviously you don't have to remember, even though I said, remember. Because if you don't remember what data type is returned by input function, simply use "type" in order to check what type of data is returned by input function. String, always string data is returned by input function. So my_age, how old am I? So, what about my age is "30". Then what happens? In print function, your_age and my_age is added. But obviously, it is not addition. You suppose to see "45 + 30" it means that "75". But, actually the return, the value is "4530". As I said before, input function, returns String. So adding two strings, adding two strings, which is concatenating, connecting two strings. Two string values are connected. In coding terminology, it is called concatenation. Two strings are connected or added. So "4530" is returned. But what about if you want to add numbers, not strings? In that case, that string information should be converted into numbers. So in that case, you use integer function, "int" function. So, string values and floating numbers are all changed it into integers. If you put that information in integer function, int function. So, in this case, what value you will get? "45 + 30", "75" will it be returned. And floating number also converted into integer. So what about "21.8" is put into integer function? Then, which value will be return? Obviously, "21" will be returned. It's like you are performing floor division of that number by one. So execute "75" and "21" is to return "75" and "21". That's what we expected to get. And so "your_age and my_age" now, they are changed into floating numbers by float function. And then, they are added.; Then what happens? "75.0" is returned. It means that this is floating number. Now, let me explain dynamic value assignment and type changing. Previously, we assigned a certain value to "x" and we are checking type of that value. And we are assigning floating number, "2.5" and checking the type again. Then we are again, assigning string value, "Arnold", and then checking type. What happens? Originally, number four is assigned to "x". Previously somewhere above, "4" is assigned to "x". Probably somewhere, where? "x" is here, "4" is assign to "x". So, in this working space, "x" object, "x" variable exist with number "4". That's the final value. Then we are reassigning another value to "x" variable, "2.5". Then it becomes class, floating number. And we are assigning a string value to the same variable "x". Then, keep changing the type and value of "x" variable. That is dynamic value assignment, and type changing. Again, before closing this video clip, there is again, Review question True or False? This is integer, floating number "4.5" is converted to an integer. Then again, "4.5" floor division by one. Then which number will be returned? "4" will be returned. This one also will be return "4" right? Because floating number 4.5 will be, if you convert that into integer "4" will return. But in this case integer number is return. In this case floating number is return. This is comparison operator, right? Are they equal? Not equal, are they the same? So, are they the same or not the same? What is your opinion? What is your answer? True or false? The answer is True because values are the same, even though the types are different. In the left side, value "4" is integer type. On the right side 4.0 it is floating number, but their value is the same. That's why they are true. So, the answer is true.
