javascript文本匹配计数和正则表达式空格不起作用

Question

我有一个问题。我正在生成一个用于文本匹配续和排序匹配计数的小脚本。 click to see jsfiddle live example

我的示例脚本:

var testtext1 = "apple banana and kiwi pineapple juice";
var testtext2 = "need apple banana pineapple milkshake";
var testtext3 = "apple pineapple lower prices";
var testtext4 = "only apple banana kiwi pineapple lovers";
var testtext5 = "kiwi pineapple apple banana sales";

alert(testtext1.match(/apple banana kiwi|apple banana|apple|banana|kiwi/gi).length); //3 matches
alert(testtext2.match(/apple banana kiwi|apple banana|apple|banana|kiwi/gi).length); //2 m
alert(testtext3.match(/apple banana kiwi|apple banana|apple|banana|kiwi/gi).length); //2 m
alert(testtext4.match(/apple banana kiwi|apple banana|apple|banana|kiwi/gi).length); //2 m
alert(testtext5.match(/apple banana kiwi|apple banana|apple|banana|kiwi/gi).length); //3 matches

text1= 只有 3 个匹配，为什么？观察正则表达式

苹果香蕉猕猴桃或苹果香蕉或苹果或香蕉或猕猴桃

苹果香蕉猕猴桃不匹配0

苹果香蕉是匹配1

苹果是匹配2

香蕉是匹配3

猕猴桃是匹配4

好吧，为什么返回 3 个匹配项而不是 4 个匹配项？和其他例子？

Answer 1

看看下面的演示

Live DEMO

用单词边界包围它，否则 pineapple 将与 apple 匹配

\b(apple banana kiwi|apple banana|apple|banana|kiwi)\b

比赛

apple banana and kiwi pineapple juice        2
need apple banana pineapple milkshake        1
apple pineapple lower prices                 1
only apple banana kiwi pineapple lovers      1
kiwi pineapple apple banana sales            2

<小时/>

编辑

如果改变顺序，结果就会不同

\b(apple|banana|apple banana kiwi|apple banana|kiwi)\b

Live DEMO

apple banana and kiwi pineapple juice        3