大家好，这里是某昨，好久不见。

动机

动动动动动机

为了拉人帮忙填坑，而会Javascript的同道又太少，某昨决定自己拟一篇教程，用来培训挖掘能够帮忙填坑的dalao。

基本语法

以下内容仅供参考。

If

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if (statement) {
  // Code here.
} else if (statement) {
  // Code here.
} else {
  // Code here.
}

Switch

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switch (statement) {
  case A:
    // Code here.
    break;
  case B:
    // Code here.
    break;
  default:
    //Code here.
    break;
}

?:

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statement ? do_if_true : do_if_false;

while

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while (statement) {
  // Code here.
}

for

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for (initial; condition; operation) {
  // Code here.
}

for … in

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// i must be declared, or declared in `for`
for (i in array) {
  // i becomes the array
  array[i] = xxx;
}

for … of

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for (item of array) {
  // item here is similiar to array[i] above.
  item = xxx;
}

declaration

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// deprecated
var variable_name = default_value;

// use now
let variable_name = default_value;

// the content of the variable can't be changed
const variable_name = default_value;

comments

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// single-line

/**
 * multiple lines
 * /

Objects

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const obj = {
  a: 1,
  b: 2
};

// here `obj` only saves the reference of that variable.
obj.a = 3;

function

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function func(arg1, arg2, ...) {
  // here arguments == [arg1, arg2, ...]
  return arguments;
}

lambda

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// arrow function
const func = () => {
  // it's a function
};

// a function returns 2i
const func_with_return = i => i * 2;

string

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const single = 'single';
const double = "double";

// equals to single + ' and ' + 'double'
const with_another_variable = `${single} and ${double}`;