107 lines
1.8 KiB
Markdown
107 lines
1.8 KiB
Markdown
---
|
|
id: 56533eb9ac21ba0edf2244da
|
|
title: 介紹 else 語句
|
|
challengeType: 1
|
|
videoUrl: 'https://scrimba.com/c/cek4Efq'
|
|
forumTopicId: 18207
|
|
dashedName: introducing-else-statements
|
|
---
|
|
|
|
# --description--
|
|
|
|
當 `if` 語句的條件爲真，會執行大括號裏的代碼。 那如果條件爲假呢？ 正常情況下什麼也不會發生。 使用 `else` 語句，可以執行當條件爲假時相應的代碼。
|
|
|
|
```js
|
|
if (num > 10) {
|
|
return "Bigger than 10";
|
|
} else {
|
|
return "10 or Less";
|
|
}
|
|
```
|
|
|
|
# --instructions--
|
|
|
|
請把多個 `if` 語句合併爲一個 `if/else` 語句。
|
|
|
|
# --hints--
|
|
|
|
應該只有一個 `if` 語句。
|
|
|
|
```js
|
|
assert(code.match(/if/g).length === 1);
|
|
```
|
|
|
|
應該使用一個 `else` 語句。
|
|
|
|
```js
|
|
assert(/else/g.test(code));
|
|
```
|
|
|
|
`testElse(4)` 應該返回字符串 `5 or Smaller`
|
|
|
|
```js
|
|
assert(testElse(4) === '5 or Smaller');
|
|
```
|
|
|
|
`testElse(5)` 應該返回字符串 `5 or Smaller`
|
|
|
|
```js
|
|
assert(testElse(5) === '5 or Smaller');
|
|
```
|
|
|
|
`testElse(6)` 應該返回字符串 `Bigger than 5`
|
|
|
|
```js
|
|
assert(testElse(6) === 'Bigger than 5');
|
|
```
|
|
|
|
`testElse(10)` 應該返回字符串 `Bigger than 5`
|
|
|
|
```js
|
|
assert(testElse(10) === 'Bigger than 5');
|
|
```
|
|
|
|
不要修改相應註釋的上面或下面的代碼。
|
|
|
|
```js
|
|
assert(/var result = "";/.test(code) && /return result;/.test(code));
|
|
```
|
|
|
|
# --seed--
|
|
|
|
## --seed-contents--
|
|
|
|
```js
|
|
function testElse(val) {
|
|
var result = "";
|
|
// Only change code below this line
|
|
|
|
if (val > 5) {
|
|
result = "Bigger than 5";
|
|
}
|
|
|
|
if (val <= 5) {
|
|
result = "5 or Smaller";
|
|
}
|
|
|
|
// Only change code above this line
|
|
return result;
|
|
}
|
|
|
|
testElse(4);
|
|
```
|
|
|
|
# --solutions--
|
|
|
|
```js
|
|
function testElse(val) {
|
|
var result = "";
|
|
if(val > 5) {
|
|
result = "Bigger than 5";
|
|
} else {
|
|
result = "5 or Smaller";
|
|
}
|
|
return result;
|
|
}
|
|
```
|