Control Flow

The control flow is the path of execution through a program.

Related concepts:  SequenceConditionalLoop

Closest Wikipedia entry:  Control flow — In computer science, control flow (or flow of control) is the order in which individual statements, instructions or function calls of an imperative program are executed or evaluated. The emphasis on explicit control flow distinguishes an imperative programming language from a declarative programming language. Within an imperative programming language, a control flow statement is a statement that results in a choice being made as to which of two or more paths to follow.

Misconceptions about Control Flow

34 documented Misconceptions

CatchAlwaysExecutes — Java

Catch blocks always get executed

CatchProvidesOptions — Java

Only the necessary part of a catch block executes

ConditionOneOutEdge — Java

A condition node in a control-flow graph can have a single outgoing edge

ConditionalIsSequence — Java

If-else is equivalent to sequence of two ifs

ConditionalIsSequence — Python

If-else is equivalent to sequence of two ifs

ConditionalIsSequence — Scratch

If-then-else block is equivalent to sequence of two if-then blocks

ConditionalOperatorNotExpression — JavaScript

The conditional operator is not an expression

DeferredReturn — Java

A return statement in the middle of a method doesn't return immediately

DeferredReturn — Python

A return statement in the middle of a function doesn't return immediately

ElsIf — Java

There is an elsif keyword for multi-way conditional statements

ElseAlwaysExecutes — Java

The else branch of an if-else statement always executes

ElseAlwaysExecutes — Scratch

The else branch of an if-then-else block always executes

ForIsConditional — Java

The body of a for statement executes at most once

IfIsLoop — Java

The body of an if statement executes repeatedly, as long as the condition holds

IfIsLoop — Python

The body of an if-statement executes repeatedly, as long as the condition holds

IfRequiresElse — Java

Every if statement requires an else

InterproceduralEdge — Java

In an intra-procedural control-flow graph, method call nodes point to the called method

LoopTerminatingCondition — Java

For and while loops end when the condition becomes true

MissingElseTerminates — Scratch

Blocks following an if without else will not execute if the condition is false

NoShortCircuit — Java

&& and || always evaluate both operands

NoShortCircuit — Python

and/or always evaluate both operands

OutsideInFunctionNesting — Python

Nested function calls are invoked outside in

PreIncrementBeforeLoop — Java

Pre-increment in update part of for loop means increment before loop body

RecursiveFunctionNeedsIfElse — Python

A recursive function needs to contain an if-else statement

RecursiveMethodNeedsIfElse — Java

A recursive method needs to contain an if-else statement

RepeatDistributes — Scratch

Each block in a loop is repeated individually

ResetStateEachLoopIteration — Scratch

The computation of all loop iterations starts from the state before the loop

ReturnNoOutEdge — Java

In a control-flow graph, a return statement has no outgoing edge

RightToLeftChaining — Python

Chained accesses are invoked from right to left

StatementMultipleOutEdges — Java

A non-condition node in a control-flow graph can have multiple outgoing edges

TryCatchMandatory — Java

If code could throw an exception, you must surround that code with a try/catch block

TryFinishes — Java

Exceptions get thrown at the end of the try block

ZeroInEdges — Java

A control-flow graph node (other than the entry node) can have zero incoming edges

ZeroOutEdges — Java

A control-flow graph node (other than the exit node) can have zero outgoing edges