if (true) {
  //true
} else {
  //false
}

while (true) {
  //alert(1);
}

var a = [1, 2, 3];
var obj = {
  name: 'name',
  value: 'value'
};
for (var i = 0; i < 10; i++) {}
function func(a, b, c) {}

c = a + b;
if (a && b || c) {
  //if
} else {
  //else
}

try {
  //try
} catch(err) {
  //catch
}

function func() {
  var a = 1,
    b = 2, 
    sum = a + b,
    obj = {
      name: 'name',
      value: 'value'
    },
  $btn = $('#btn');
  //函数体
}

var i, arr = [];
for (i = arr.length; i--;) {
  //arr[i];
}

for (var i = 0; i < document.getElementsByName().length; i++) {
  //document.getElementsByName()[0];
}

var arr = [], 
  i = arr.length;
while (i--) {
  //处理
}

var i,
  hasOwn = Object.prototype.hasOwnProperty;
for (i in man) {
  if (hasOwn.call(man, i)) { //过滤
    console.log(i, ':', man[i]);
  }
}

switch (num) {
case 0:
  //do something
  break;
case 1:
  //do something
  break;
...
default:
  //do default
}

var obj = {
  '0': function() {
    //do somethins
  },
  '1': function() {
    // do somethis
  }, ...
}
if (obj.hasOwnProperty(num)) {
  obj[num]();
} else {
  //do default
}

var month = '09', day = '08';
month = parseInt(month, 10); //不加进制参数便会转换为八进制
day = parseInt(day, 10);

+'08';
Number('08');

// built in constructors (avoid)
var o = new Object();
var a = new Array();
var re = new RegExp('[a-z]', 'g');
var s = new String();
var n = new Number();
var b = new Boolean();
throw new Error('message');

// literals and primitives (prefer)
var o = {};
var a = [];
var re = /[a-z]/g;
var s = '';
var n = 0;
var b = false;
throw {
  name: 'Error',
  message: 'message'
}