MIT 6.096 Intruduction to C++ 复习笔记 #02

课程链接：https://ocw.mit.edu/courses/e...

L.02 Flow of Control

1. Motivation

Alter the order in which a program's statements are excuted, the control flow.

2. Contorl Structure

2.1 Conditionals

1. Relational operator: >, < , ==, !=, <=, etc.
2. Logical operator: &&(and), ||(or), !(not)

2.1.1 if, if-else and else if

1. if conditional:

if(condition){
    statement 1
    statement 1
    ...
}
if(condition)
    statement only 1

1. if-else conditional:

if(condition){
    statement 1
    statement 2
    ...
}else{
    statement 3
    statement 4
}

if(condition)
    statement only 1a
else
    statement only 1b

1. if-else if conditional:

if(condition){
    statement 1
    statement 2
    ...
}else if(condition){
    statement 3
    statement 4
}

2.1.2 switch

May or may not excute certain statements.

switch(expression){
    case constant1:
         statementA1
         statementA2
         ...
         break;
    case constant2:
         statementB1
         statementB2
         ...
         break;
    ...
    default:
        statementZ1
        statementZ2
        ...
}

2.2 Loops

2.2.1 while and do-while

while (condition){
    statement 1
    statement 2
    ...
}
while (condition)
    statement only 1

do{
    statement 1
    statement 2
    ...
}
while(condition);

Note: Statement 1&2 in do-while will be excuted one time at least.

2.2.2 for

for (initialization; condition; incrementation){
    statement 1;
    statement 2;
}

// the counter already defined, no need to get a new one
for (; i<10; i=i+1){
    statement;
}

// From 0 to 9, 10 times in total
for (int i=0; i<10; i=i+1){
    statement;
}

2.2.3 Equivalent loops

for(initialization; condition; increment){
    statement;
}

// Rewrite

initialization;
while(condition){
    statement;
    increment;
}