Abstraction Introduction to Computer Science 2015 Project Lead

Abstraction • Generalizing • Removing detail Introduction to Computer Science © 2015 Project Lead

Abstraction • Procedural abstraction naming a procedure • Data abstraction standardizing a way to represent data • Model abstraction using some parameters and not others Introduction to Computer Science © 2015 Project Lead The Way, Inc.

Procedural Abstraction • Give a name to a procedure that can be used over

The Ladder of Abstraction application software for thing in room: pick_up(thing) high-level language COBOL C low-level language Grace Hopper en. wikipedia. org/wiki/File: Intel_80486 DX 2_bottom. jpg bytes and bits voltage and current physics Introduction to Computer Science int register c; 01010010 101011111011 01000101 0111110 - + + + - http: //en. wikipedia. org/wiki/File: Transistorer. jpg N P N http: //thelovef orhistory. wor dpress. com/2 011/05/24/ein stein © 2015 Project Lead The Way, Inc.

CPU Follows a Sequence of Instructions • CPU is the Central Processing Unit: one “core” • Programs are turned into instructions understood by the CPU en. wikipedia. org/wiki/File: E 6750 bs 8. jpg Introduction to Computer Science © 2015 Project Lead The Way, Inc.

Typing Code That Makes Sense Closer to Human Language Thankfully, Grace Hopper invented the compiler, a computer program that lets programmers work with more human-readable language. A compiler translates a more human-friendly code into a sequence of assembly language code before the code runs. Grace Hopper called her new language COBOL. She received a B. S. in mathematics from Vassar College and a Master’s and Ph. D. from Harvard. She programmed the Mark I, II, and III computers and was a Rear Admiral in the U. S. Navy. Grace Hopper 1906 -1992 Introduction to Computer Science © 2015 Project Lead The Way, Inc.