JavaScript中join()、splice()、slice()和split()函数用法示例

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本文实例讲述了JavaScript中join()、splice()、slice()和split()函数用法。分享给大家供大家参考，具体如下：

join()

join() 方法用于把数组中的所有元素放入一个字符串。

元素是通过指定的分隔符进行分隔的。

<script type="text/javascript">
var arr = new Array(3)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
document.write(
arr.join()
)
</script>

运行结果：

George,John,Thomas

<script type="text/javascript">
var arr = new Array(3)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
document.write(
arr.join(".")
)
</script>

运行结果：

George.John.Thomas

split()

split() 方法用于把一个字符串分割成字符串数组。

<script type="text/javascript">
var str="How are you doing today?"
document.write(str.split(" ") + "<br />")
document.write(str.split("") + "<br />")
document.write(str.split(" ",3))
</script>

运行结果：

How,are,you,doing,today?
H,o,w, ,a,r,e, ,y,o,u, ,d,o,i,n,g, ,t,o,d,a,y,?
How,are,you

"2:3:4:5".split(":") //将返回["2", "3", "4", "5"]
"|a|b|c".split("|") //将返回["", "a", "b", "c"]
"hello".split("") //可返回 ["h", "e", "l", "l", "o"]
"hello".split("", 3) //可返回 ["h", "e", "l"]

slice()

slice() 方法可从已有的数组中返回选定的元素。

<script type="text/javascript">
var arr = new Array(3)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
document.write(arr + "<br />")
document.write(
arr.slice(1)
 + "<br />")
document.write(arr)
</script>

运行结果：

George,John,Thomas
John,Thomas
George,John,Thomas

<script type="text/javascript">
var arr = new Array(6)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
arr[3] = "James"
arr[4] = "Adrew"
arr[5] = "Martin"
document.write(arr + "<br />")
document.write(
arr.slice(2,4)
 + "<br />")
document.write(arr)
</script>

运行结果：

George,John,Thomas,James,Adrew,Martin
Thomas,James
George,John,Thomas,James,Adrew,Martin

splice()

splice() 方法向/从数组中添加/删除项目，然后返回被删除的项目。

注释：该方法会改变原始数组。

<script type="text/javascript">
var arr = new Array(6)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
arr[3] = "James"
arr[4] = "Adrew"
arr[5] = "Martin"
document.write(arr + "<br />")
arr.splice(2,0,"William")
document.write(arr + "<br />")
</script>

运行结果：

George,John,Thomas,James,Adrew,Martin
George,John,William,Thomas,James,Adrew,Martin

<script type="text/javascript">
var arr = new Array(6)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
arr[3] = "James"
arr[4] = "Adrew"
arr[5] = "Martin"
document.write(arr + "<br />")
arr.splice(2,1,"William")
document.write(arr)
</script>

运行结果：

George,John,Thomas,James,Adrew,Martin
George,John,William,James,Adrew,Martin

<script type="text/javascript">
var arr = new Array(6)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
arr[3] = "James"
arr[4] = "Adrew"
arr[5] = "Martin"
document.write(arr + "<br />")
arr.splice(2,3,"William")
document.write(arr)
</script>

运行结果：