Use of the concat () method of JavaScript __java

In sql: For Example Select Concat (' AA ', ' BB ');------------the final display is AABB, at the same time, Concat has to_char role, is to convert other types of varchar type of


Select Concat (NAME, ': ', TITLE) from person p WHERE p.id = ID

The result is： Danny:java
JavaScript concat () method

JavaScript Array Object definitions and usage

The Concat () method is used to connect two or more arrays.

This method does not change an existing array, but merely returns a copy of the connected array. Grammar

Arrayobject.concat (Arrayx,arrayx,......, Arrayx)

Parameters	Description
Arrayx	Necessary. The parameter can be a specific value, or it can be an array object. Can be any number of.

return value

Returns a new array. The array is generated by adding all the Arrayx parameters to the Arrayobject. If the argument for the concat () operation is an array, then the element in the array is added, not the array. instance Example 1

In this case, we'll connect the arguments in concat () to array A:

<script type= "Text/javascript" >

var a = [1,2,3];
document.write (A.concat (4,5));

</script>

Output:

1,2,3,4,5

Example 2

In this case, we created two arrays and then connected them using Concat ():

<script type= "Text/javascript" >

var arr = new Array (3)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"

var arr2 = new Array (3)
arr2[0] = "James"
arr2[1] = "Adrew"
arr2[2] = "Martin"

docume Nt.write (Arr.concat (arr2))

</script>

Output:

George,john,thomas,james,adrew,martin

Example 3

In this case, we created three arrays and then connected them using Concat ():

<script type= "Text/javascript" >

var arr = new Array (3)
arr[0] = "George"
arr[1] = "John"
arr[2] = " Thomas "

var arr2 = new Array (3)
arr2[0] =" James "
arr2[1] =" Adrew "
arr2[2] =" Martin "

var arr3 = new Array (2)
arr3[0] = "William"
arr3[1] = "Franklin"

document.write (Arr.concat (ARR2,ARR3))

</ Script>

Output:

George,john,thomas,james,adrew,martin,william,franklin