Chapter 8: Iterate And Display Project

In this project, we will create a loop that builds a list of values based on user input and prints them out to the terminal.

To start, we need to create a loop that gets user input, and initializes our newly found list type:

obj inputs = [];

while true {

    obj text = chew("Enter some text: ");

}

Let's add the typed text to our list object:

obj inputs = [];

while true {

    obj text = chew("Enter some text: ");

    obj inputs = push(inputs, text);

}

For now, this just creates an infinite loop slowly building a list based on user input. It might be helpful to check the length of the list and stop the loop eventually:

obj inputs = [];

while true {

    if length(inputs) == 5 {

        leave;

    }

    obj text = chew("Enter some text: ");

    obj inputs = push(inputs, text);

}

This will stop the program once we hit 5 items pushed to the list. You can check the size of a list or string with length.

Now what about the display part? We need a way to iterate through the list. The most common way is to use the walk loop like so:

walk i = 0 through length(inputs) {

    bark(i);

}

This will print each index the size of length(inputs). We can then retrieve that index to get the value at that point in the list:

walk i = 0 through length(inputs) {

    bark(retrieve(inputs, i));

}

Now that we can iterate through the list, we can use the std_format module to format our text with the value in the list:

fetch std_format; # imports the std_format module, we'll touch on this later

# ...

walk i = 0 through length(inputs) {

    bark(format("You typed 5 items, one of them was: {}", retrieve(inputs, i)));

}

And boom! Run your program, type 5 individual things, and see the output!

The final end program should look something like:

fetch std_format;

obj inputs = [];

while true {

    if length(inputs) == 5 {

        leave;

    }

    obj text = chew("Enter some text: ");

    obj inputs = push(inputs, text);

}

walk i = 0 through length(inputs) {

    bark(format("You typed 5 items, one of them was: {}", retrieve(inputs, i)));

}