各章节AP计算机科学知识点梳理（上）

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AP计算机科学知识点 AP计算机

计算机作为当前最被看好的一大专业领域，很多同学们在AP课程学习期间会选修AP计算机科学这门课来帮助自己打好知识基础。今天易伯华国际教育小编就带大家梳理一下各章节中AP计算机知识点内容，来帮助同学们更为系统地开展AP计算机科学的学习和备考工作。

1. Introductory Java Language Features

Package And Classes 类和包

public class FirstProg // file name is FirstProg.java { public static type1 method1 (parameter list) { public static type2 method2 (parameter list) { ...... public static void main (String[] args) {

All java methods must be contained in a class; all program statement must be placed in a method

The class that contains the main method does not contain many additional methods.

reserved words (Keywords): class, public, static, void, main.

public: the class or method is usable outside of the class

static: methods that will not access any objects of a class. The main method must always be static.

Types And Identifiers 标识符和类型

Identifiers 标识符

Identifier: name for a variable, parameter, constant, user-defined method, user-defined class

cannot begin with a digit

Lowercase: for variables and methods

Uppercase: separate into multiple words e.g getName, findSurfaceArea

a class name starts with a capitol letter

Built-in Types 内置类型

int - 整数 boolean - true or false double - 小数

Storage of Numbers 数值储存

Integers 整数 binary Integer.MAX_VALUE == 2^31-1 Integer.MIN_VALUE == - 2^31 Floating-Point Numbers 浮点数 float & double

sign * mantissa * 2^exponent

round-off error - when floating-point numbers are converted into binary, most cannot be represented exactly

e.g 0.1*26 ≠ 0.1+0.1......(26 terms)

NaN"not a number" - undefined number

Hexadecimal Numbers 十六进制数

conversion between hex and binary 5 hex = 0101 bin F hex = 1111 bin 5F hex = 01011111 bin

Final Variable Final变量

user-defined constant

keyword final

e.g. final double TAX_RATE = 0.08;

final variable can be declared without initializing it immediately, but can only be given just once

array bound

final int MAXSTUDENTS = 25;

int [] classList = new Int[MAXSTUDENTS];

Operators 运算符

Arithmetic Operators 算数运算符

+ addition - subtraction * multiplication /devision %mod(remainder)

Relational Operators 关系运算符

== equal to != not equal to greater than less than = greater or equal to = less than or equal to

Relational Operators can only be used in comparison of primitive types.

User defined types : equals, compareTo methods

floating-point should not be compared directly using relational operators.

Logical Operators 逻辑运算符

! NOT && AND || OR Short-circuit evaluation evaluated from left to right evaluation automatically stops as soon as the value of the entire expression is known

Assignment Operators 赋值运算符

Compound assignment operators : = += -= *= /= %=

Increment and Decrement Operator 递增递减运算符

++ --

Operator Precedence 运算符的优先级

!, ++ , --

right to left

* , / , %

left to right + , -

left to right ,, =,= left to right == , !=

left to right && || =, +=, -+, *=, /=, %= right to left

Input/Output 输入输出

Escape sequences 转义字符

\n newline \" double quot \\ backslash

Control Structures 控制结构

Decision-Making Control Structures 条件结构

if...

if...else...

nested if

extended if (if...elseif...)

Iteration 循环结构

for loop

for (initialization; termination condition; update statement)

The termination condition is tested at the top of the loop

the update statement is performed at the bottom

loop variable should not have its value changed inside the loop body

the scope of the loop variable can be restricted to the loop body by combining the loop variable declaration with the initialization.

for-each loop

for (SomeType element : collection)

cannot be used to replace or remove elements

hides the index variable that is used with array

while loop

while (boolean test)以上就是易伯华国际教育小编关于部分AP计算机科学知识点内容的梳理，当然由于篇幅有限，小编只更新了部分内容，其余部分将在接下来几天中列举。欢迎持续关注哟！