Sequential Languages

A programming language is characterized by two things: a philosophy of programming and details of notation. Most modern programming languages are multi-paradigm but basically sequential. This includes Snap!, even though you have learned some composition (nesting) of functions (known as functional programming) and some ideas about sprites as objects (object-oriented programming).

Learning another language of the same type is much easier than learning your first one. For example, here’s the binary search function from Lab 1 of this unit:

Python

Here's the same procedure written in Python:

def binary_search(value, data):
    low = 0
    high = len(data)-1
    while (low <= high):
        current_index = average(low, high)    # find the middle word
        current_item = data[current_index]
        if (current_item == value):
            return True
        elif (current_item > value):          # eliminate half the list
            high = current_index-1
        else:
            low = current_index+1
    return False

For the most part, this is line-for-line the same as the Snap! version, apart from tiny details such as

return

instead of . There are also several more significant differences in notation.

JavaScript

Here's the same binary search procedure written in JavaScript:

function binarySearch(value, data) {
    var low, high, currentIndex, currentItem;
    low = 0;
    high = len(data)-1;
    while (low <= high) {
        currentIndex = average(low, high);    // find the middle word
        currentItem = data[currentIndex];
        if (currentItem == value) {
            return true;
        } else if (currentItem > value) {     // eliminate half the list
            high = currentIndex-1;
        } else {
            low = currentIndex+1;
        }
    }
    return false;
}

This doesn't look so different from the Python version, but there are a few significant differences.

Learning Another Sequential Language

There are things to learn about notation (syntax, which is the text-language equivalent of block colors and shapes). But you will be able to learn the details of one of these other languages much more quickly now because you've learned Snap!. You already know how to program in a sequential language!