attribute
constructor: returns a reference to the array function that created this object.
The constructor property returns a reference to the array function that created this object
var test=new Array();
if (test.constructor==Array)
{
document.write("This is an Array");
}
if (test.constructor==Boolean)
{
document.write("This is a Boolean");
}
if (test.constructor==Date)
{
document.write("This is a Date");
}
if (test.constructor==String)
{
document.write("This is a String");
}
</script>The output result is:
This is an Array
length: sets or returns the number of elements in the array.
The length property sets or returns the number of elements in the array
var arr = new Array(3)
arr[0] = "John"
arr[1] = "Andy"
arr[2] = "Wendy"
document.write("Original length: " + arr.length)
document.write("<br />")
arr.length=5
document.write("New length: " + arr.length)
</script>The output result is:
Original length: 3
New length: 5
prototype: enables you to add properties and methods to objects.
The prototype attribute is relative to the attributes and methods you want to add
function employee(name,job,born)
{
this.name=name;
this.job=job;
this.born=born;
}
var bill=new employee("Bill Gates","Engineer",1985);
employee.prototype.salary=null;
bill.salary=20000;
document.write(bill.salary);
</script>The output result is:
20000
method
concat(): concatenate two or more arrays and return results.
The concat() method connects two or more arrays and returns the result
var a = [1,2,3]; document.write(a.concat(4,5)); </script>
The output result is:
1,2,3,4,5
join(): put all elements of the array into a string. Front end training Elements are separated by the specified separator.
The join() method puts all the elements of the array into a string, separated by the specified separator
var arr = new Array(3) arr[0] = "George" arr[1] = "John" arr[2] = "Thomas" document.write(arr.join()) </script>
The output result is:
George,John,Thomas
pop(): deletes and returns the last element of the array
The pop() method deletes and returns the last element of the array
var arr = new Array(3)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
document.write(arr)
document.write("<br />")
document.write(arr.pop())
document.write("<br />")
document.write(arr)
</script>The output result is:
George,John,Thomas
Thomas
George,John
push(): adds one or more elements to the end of the array and returns the new length.
The push() method adds one or more elements to the end of the array and returns a new length.
var arr = new Array(3)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
document.write(arr + "<br />")
document.write(arr.push("James") + "<br />")
document.write(arr)
</script>The output result is:
George,John,Thomas
4
George,John,Thomas,James
reverse(): reverse the order of the elements in the array.
The reverse() method reverses the order of the elements in the array
var arr = new Array(3) arr[0] = "George" arr[1] = "John" arr[2] = "Thomas" document.write(arr + "<br />") document.write(arr.reverse()) </script>
The output result is:
George,John,Thomas
Thomas,John,George
shift(): deletes and returns the first element of the array
The shift() method deletes and puts back the first element of the array
var arr = new Array(3) arr[0] = "George" arr[1] = "John" arr[2] = "Thomas" document.write(arr + "<br />") document.write(arr.shift() + "<br />") document.write(arr) </script>
The output result is:
George,John,Thomas
George
John,Thomas
slice(): returns the selected element from an existing array
The slice() method returns the selected element from an existing array
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>
Output results:
George,John,Thomas
John,Thomas
George,John,Thomas
sort(): sort the elements of the array
The sort() method is to sort the elements of the array
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.sort()) </script>
The output result is:
George,John,Thomas,James,Adrew,Martin
Adrew,George,James,John,Martin,Thomas
splice(): delete the element and add a new element to the refrigerator array
The splice() method deletes the element and adds a new element to the array
Example: create a new array and add an element to it
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>
The output result is:
George,John,Thomas,James,Adrew,Martin
George,John,William,Thomas,James,Adrew,Martin
Example: delete the element at i[2] and add a new element to replace the deleted element
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>
The output result is:
George,John,Thomas,James,Adrew,MartinGeorge,John,William,James,Adrew,Martin
toSource(): returns the source code of the object
The toSource() method returns the source code of the object
function employee(name,job,born)
{
this.name=name;
this.job=job;
this.born=born;
}
var bill=new employee("Bill Gates","Engineer",1985);
document.write(bill.toSource());
</script>The output result is:
({name:"Bill Gates", job:"Engineer", born:1985})
toString(): converts an array into a string and returns the result
The toString() method converts an array into a string and returns the result
var arr = new Array(3) arr[0] = "George" arr[1] = "John" arr[2] = "Thomas" document.write(arr.toString()) </script>
The output result is:
George,John,Thomas
toLocaleString(): converts an array into a local array and returns the result
The toLocaleString() method converts the array to a local array and returns the result
var arr = new Array(3) arr[0] = "George" arr[1] = "John" arr[2] = "Thomas" document.write(arr.toLocaleString()) </script>
The output result is:
George, John, Thomas
unshift(): add one or more elements like the beginning of the array and return the length of the array
The unshift() method adds one or more elements like the beginning of the array and returns the length of the array
var arr = new Array()
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
document.write(arr + "<br />")
document.write(arr.unshift("William") + "<br />")
document.write(arr)
</script>Output results:
George,John,Thomas
William,George,John,Thomas
valueOf(): returns the original value of the array object.
The valueOf() method returns the original value of the array object.
Syntax:
arrayObject.valueOf()