// Comment...

/* Comment... */

// A one line comment.

/* A comment that goes onto 
more than one line */

if (test) {
    if-clause
} 
else {
    else-clause
}

test:

Evaluates to true or false.

if-clause:

Executed if test==true.

else-clause:

Execued if test==false. The else-clause is optional.

// add 3 to x if non-neg.

if (x >= 0) {
    x = x + 3;
}



// decrement x if neg.,
//   otherwise increment

if (x < 0) {
    x = x - 1;
}
else {
    x = x + 1;
}

while (test) {
    loop-body
}

test:

Evaluates to true or false. If test==true the loop body is executed and the test is performed again.

// sum = x+(x-1)+...+3+2+1

sum = 0;
while (x >= 1) {
    sum = sum + x;
    x = x - 1;
}

for (init; test; action) {
    loop-body
}

init:

Evaluated once when the for loop is first reached.

test:

If test==true the loop body will execute.

action:

Executed after the loop body and before the next evaluation of test.

// sum = 1+2+3+...+x

sum = 0;
for (i = 1; i <= x; i = i + 1) {
    sum = sum + i;
}



// fact = 1*2*3*...*10

fact = 1;
for (j = 2; j <= 10; j = j + 1) {
    fact = fact * j;
}

function FuncName(param1, param2,...) 
{
    variable-declarations

    function-body
    
    return return-value;
}

FuncName:

The name of the function.

param1:

The name of the first parameter passed to the function.

variable-declarations:

list of local variables (if any) that appear in the function, preceded by var.

function-body:

JavaScript statements to be executed when the function is called.

return-value:

Value that is returned from this function. The return statement is optional.

function FooFunc() 
// Returns:  the string "foo"
{
    return "foo";
}



function BarFunc(N)
// Assumes: N >= 0
// Returns: string of N "bar"s
{
    var i, theStr;

    theStr = "";
    for (i = 1; i <= N; i = i + 1) {
        theStr = theStr+"bar";
    }
    return theStr;
}


function Greet(name)
// Assumes: name is a string
// Results: displays greeting
{
    document.write("Hi "+name);
}

myVar = FuncName(arg1, arg2,...);

myVar:

Variable to hold the value (if any) returned by the function.

FuncName:

Name of the function to call.

arg1:

Argument 1, the value for the first parameter of the function.

Str1 = FooFunc();

// Result: Str1 == "foo" 



Str2 = BarFunc(3);

// Result: Str2 == "barbarbar"



Greet("Oliver");

// Result: displays "Hi Oliver"