1.2.4 Types of Programming Language

Are approaches to using a program language to solve problems.

imperative and decleartive

Code clearly specify the action to be preformed

Focus on declaring the desired result. Details on how its obtained are abstracted from the user

procedual - python oop

functional - reusing func logic - quries to find problem - sql

Easy to implement ,not possible to solve all problems or maybe ineff

Sequence - execute line by line top to bottom Selection - Code is run if a specific condition is met iteration - code is run a # of time or while condtion true Recursion - Func are expression in terms of themselves until conditions is met known as base case

is suited to probelsm that can be easly be expressed as a series of instructions

Next level up from machine code low level language converted to machine code using an assembler

language based on instruction set of the computer

uses mnemonics rather then binary easier to use than direct machine code. Mnemoics represent numeric code Processor specific as it directly interacts with cpu purpose register

useful for embedded ssytems as allows for direct interactions with hardware

AS SLIO HD BBB ADD > add > adds values @ memory and acc SUB > subtract > sub value @ memory from acc STA > store > Value at acc at address LDA > load > value at mm to acc INP > input > user input stored to acc OUT > output > print value at acc HLT > halt > stops execution DAT > data > flag w/ label with data is stored BRZ > branch if 0 > *BR is zero *CB BRP > branch if + > *BR is positive *CB BRA > branch always > branch to given address no matter of acc value, uncoditonal branch *BR = branch to given address if acc value CB - conditonal branch

opcode and operand

Holds the specific instructions to be preformed

holds the value releated to data on which is instruction is run

Requires less code: operand address is directly specified in the instruction, Less complex: requires fewer instructions and is generally easier to debug it is not useful for accessing complex data structures such as arrays and records that are used in high-level languages

immediate addressing Direct addressing Indirect addressing indexing addressing

The operand is the value which the instruction uses

operand gives the address which holds the value

operand gives the address of a register which holds another address where the data is held

index register used stores value address of operand determind by adding operand This is necessary to add an offset in order to access data stored contiguously in mmemory such as in arrays

attempts to capture or group infomation / data and code into structed items known as objects