JS Statements

gistfile1.txt

expression
if
switch
while
do
for
break
continue
return
try/throw

Break statement
Statements an have labels
Break statements can refer to those labels

loop: for (;;) {
  ...
    if (...) {
      break loop;
    }
  ...
}

For statement
Iterate through all of the elements of an array:

for (i=0; i < array.length; i += 1) {
  // within the loop, 
  // i  is the index if the current member
  // array[i] is the current element
}

// sometimes you might see for (var i = 0;
// the recommended way of declaring i is to declare before the for loop
// var i = 0; 
// i can be declared and initialized 
// if done this way use: for (; i < array .length; i += 1) {...}

For in statement
Iterate through all of the members of an object:

for (name in object) {
  if (object.hasOwnProperty(name)) {
    
    // within the loop,
    // name is the key of current member
    // object[name] is the current value
    
  }
}

Switch statement
Multiway branch.
The switch value does not need to be a number.  It can be a string.
The case values can be expressions.
Danger: Cases fall through to the next case unless a disruptive statement like break ends the case.

switch (expression) {
case ';':
case ';':
case '.':
  punctuation();
  break;
default:
  noneOfTheAbove();
}

Throw statement

throw new Error(reason);

throw {
  name: exceptionName,
  message: reason
};

Try statement

try {
  ...
} case (e) {
  switch (e.name) {
  case 'Error':
    ...
    break;
  default:
    throw e;
  }
}

Try can produce:
'Error'
'EvalError'
'RangeError'
'SyntaxError'
'TypeError'
'URIError'