javascript-tutorial · leviding · Apr 27, 2018 · Apr 23, 2018 · Apr 23, 2018 · Apr 23, 2018
diff --git a/1-js/02-first-steps/11-logical-operators/1-alert-null-2-undefined/solution.md b/1-js/02-first-steps/11-logical-operators/1-alert-null-2-undefined/solution.md
@@ -1,4 +1,4 @@
-The answer is `2`, that's the first truthy value.
+结果是 `2`，这是第一个真值。
 
 ```js run
 alert( null || 2 || undefined );

diff --git a/1-js/02-first-steps/11-logical-operators/1-alert-null-2-undefined/task.md b/1-js/02-first-steps/11-logical-operators/1-alert-null-2-undefined/task.md
@@ -2,9 +2,9 @@ importance: 5
 
 ---
 
-# What's the result of OR?
+# 或运算的结果是什么？
 
-What the code below is going to output?
+如下代码将会输出什么？
 
 ```js
 alert( null || 2 || undefined );

diff --git a/1-js/02-first-steps/11-logical-operators/2-alert-or/solution.md b/1-js/02-first-steps/11-logical-operators/2-alert-or/solution.md
@@ -1,13 +1,13 @@
-The answer: first `1`, then `2`.
+答案：首先是 `1`，然后是 `2`。
 
 ```js run
 alert( alert(1) || 2 || alert(3) );
 ```
 
-The call to `alert` does not return a value. Or, in other words, it returns `undefined`.
+对 `alert` 的调用没有返回值。或者说返回的是 `undefined`。
 
-1. The first OR `||` evaluates it's left operand `alert(1)`. That shows the first message with `1`.
-2. The `alert` returns `undefined`, so OR goes on to the second operand searching for a truthy value.
-3. The second operand `2` is truthy, so the execution is halted, `2` is returned and then shown by the outer alert.
+1. 第一个或运算 `||` 对它的左值 `alert(1)` 进行了计算。这就显示了第一条 `1` 的信息。
+2. 函数 `alert` 返回了 `undefined`，所以或运算继续检查第二个操作数，寻找真值。
+3. 第二个操作数 `2` 是真值，所以执行就中断了。`2` 被返回，并且被外层的 alert 显示。
 
-There will be no `3`, because the evaluation does not reach `alert(3)`.
+不会显示 `3`，因为运算没有抵达 `alert(3)`。
diff --git a/1-js/02-first-steps/11-logical-operators/2-alert-or/task.md b/1-js/02-first-steps/11-logical-operators/2-alert-or/task.md
@@ -2,9 +2,9 @@ importance: 3
 
 ---
 
-# What's the result of OR'ed alerts?
+# 或运算和 alerts 的结果是什么？
 
-What the code below will output?
+下面的代码将会输出什么？
 
 ```js
 alert( alert(1) || 2 || alert(3) );

diff --git a/1-js/02-first-steps/11-logical-operators/3-alert-1-null-2/solution.md b/1-js/02-first-steps/11-logical-operators/3-alert-1-null-2/solution.md
@@ -1,4 +1,4 @@
-The answer: `null`, because it's the first falsy value from the list.
+答案：`null`，因为它是列表中第一个假值。
 
 ```js run
 alert( 1 && null && 2 );

diff --git a/1-js/02-first-steps/11-logical-operators/3-alert-1-null-2/task.md b/1-js/02-first-steps/11-logical-operators/3-alert-1-null-2/task.md
@@ -2,9 +2,9 @@ importance: 5
 
 ---
 
-# What is the result of AND?
+# 与操作的结果是什么？
 
-What this code is going to show?
+下面这段代码将会显示什么？
 
 ```js
 alert( 1 && null && 2 );

diff --git a/1-js/02-first-steps/11-logical-operators/4-alert-and/solution.md b/1-js/02-first-steps/11-logical-operators/4-alert-and/solution.md
@@ -1,10 +1,10 @@
-The answer: `1`, and then `undefined`.
+答案：`1`，然后 `undefined`。
 
 ```js run
 alert( alert(1) && alert(2) );
 ```
 
-The call to `alert` returns `undefined` (it just shows a message, so there's no meaningful return).
+调用 `alert` 返回了 `undefined`（它只展示消息，所以没有有意义的返回值）。
 
-Because of that, `&&` evaluates the left operand (outputs `1`), and immediately stops, because `undefined` is a falsy value. And `&&` looks for a falsy value and returns it, so it's done.
+因此，`&&` 计算了它左边的操作数（显示 `1`），然后立即停止了，因为 `undefined` 是一个假值。并且 `&&` 就是寻找假值然后返回它，所以运算结束。
 
diff --git a/1-js/02-first-steps/11-logical-operators/4-alert-and/task.md b/1-js/02-first-steps/11-logical-operators/4-alert-and/task.md
@@ -2,9 +2,9 @@ importance: 3
 
 ---
 
-# What is the result of AND'ed alerts?
+# 与运算连接的 alerts 的结果是什么？
 
-What will this code show?
+这段代码将会显示什么？
 
 ```js
 alert( alert(1) && alert(2) );

diff --git a/1-js/02-first-steps/11-logical-operators/5-alert-and-or/solution.md b/1-js/02-first-steps/11-logical-operators/5-alert-and-or/solution.md
@@ -1,16 +1,16 @@
-The answer: `3`.
+答案：`3`。
 
 ```js run
 alert( null || 2 && 3 || 4 );
 ```
 
-The precedence of AND `&&` is higher than `||`, so it executes first.
+与运算 `&&` 的优先级比 `||` 高，所以它第一个被执行。
 
-The result of `2 && 3 = 3`, so the expression becomes:
+结果是 `2 && 3 = 3`，所以表达式变成了：
 
 ```
 null || 3 || 4
 ```
 
-Now the result if the first truthy value: `3`.
+现在的结果就是第一个真值：`3`。
 
diff --git a/1-js/02-first-steps/11-logical-operators/5-alert-and-or/task.md b/1-js/02-first-steps/11-logical-operators/5-alert-and-or/task.md
@@ -2,9 +2,9 @@ importance: 5
 
 ---
 
-# The result of OR AND OR
+# 或运算、与运算、或运算串联的结果
 
-What will be the result?
+结果将会是什么？
 
 ```js
 alert( null || 2 && 3 || 4 );

diff --git a/1-js/02-first-steps/11-logical-operators/6-check-if-in-range/task.md b/1-js/02-first-steps/11-logical-operators/6-check-if-in-range/task.md
@@ -2,8 +2,8 @@ importance: 3
 
 ---
 
-# Check the range between
+# 检查值是否位于范围区间内
 
-Write an "if" condition to check that `age` is between `14` and `90` inclusively.
+写一个“if”条件句来检查 `age` 是否位于 `14` 到 `90` 的闭区间。
 
-"Inclusively" means that `age` can reach the edges `14` or `90`.
+“闭区间”意味着，`age` 的值可以取 `14` 或 `90`。
diff --git a/1-js/02-first-steps/11-logical-operators/7-check-if-out-range/solution.md b/1-js/02-first-steps/11-logical-operators/7-check-if-out-range/solution.md
@@ -1,10 +1,10 @@
-The first variant:
+第一个表达式：
 
 ```js
 if (!(age >= 14 && age <= 90))
 ```
 
-The second variant:
+第二个表达式：
 
 ```js
 if (age < 14 || age > 90)

diff --git a/1-js/02-first-steps/11-logical-operators/7-check-if-out-range/task.md b/1-js/02-first-steps/11-logical-operators/7-check-if-out-range/task.md
@@ -2,8 +2,8 @@ importance: 3
 
 ---
 
-# Check the range outside
+# 检测值是否位于范围之外
 
-Write an `if` condition to check that `age` is NOT between 14 and 90 inclusively.
+写一个 `if` 条件句，检查 `age` 是否不位于 14 到 90 的闭区间。
 
-Create two variants: the first one using NOT `!`, the second one -- without it.
+创建两个表达式：第一个用非运算 `!`，第二个不用。
diff --git a/1-js/02-first-steps/11-logical-operators/8-if-question/solution.md b/1-js/02-first-steps/11-logical-operators/8-if-question/solution.md
@@ -1,19 +1,19 @@
-The answer: the first and the third will execute.
+答案：第一个和第三个将会被执行。
 
-Details:
+详解：
 
 ```js run
-// Runs.
-// The result of -1 || 0 = -1, truthy
+// 执行。
+// -1 || 0 的结果为 -1，真值
 if (-1 || 0) alert( 'first' );
 
-// Doesn't run
-// -1 && 0 = 0, falsy
+// 不执行。
+// -1 && 0 = 0，假值
 if (-1 && 0) alert( 'second' );
 
-// Executes
-// Operator && has a higher precedence than ||
-// so -1 && 1 executes first, giving us the chain:
+// 执行
+// && 运算的优先级比 || 高
+// 所以 -1 && 1 先执行，给出如下运算链：
 // null || -1 && 1  ->  null || 1  ->  1
 if (null || -1 && 1) alert( 'third' );
 ```

diff --git a/1-js/02-first-steps/11-logical-operators/8-if-question/task.md b/1-js/02-first-steps/11-logical-operators/8-if-question/task.md
@@ -2,11 +2,11 @@ importance: 5
 
 ---
 
-# A question about "if"
+# 一个关于 "if" 的问题
 
-Which of these `alert`s are going to execute?
+下面哪一个 `alert` 将会被执行？
 
-What will be the results of the expressions inside `if(...)`?
+`if(...)` 语句内表达式的结果是什么？
 
 ```js
 if (-1 || 0) alert( 'first' );