Home > Web Front-end > JS Tutorial > body text

The usage of tostring() and valueof() and the difference between them

PHP中文网
Release: 2017-05-25 14:45:40
Original
2300 people have browsed it

Basically, all JS data types have two methods, valueOf and toString, except null. The two of them solve the problem of javascript value operation and display.

1. The usage is as follows:

toString() method: Returns the string representation of the object.

Object Operation
Array Convert the elements of Array is a string. The resulting strings are comma separated and concatenated.
Boolean If the Boolean value is true, return "true". Otherwise, returns "false".
Date Returns the text representation of the date.
Error Returns a string containing the relevant error message.
Function returns a string in the following format, where functionname is the name of the called toString method function:
function functionname( ) { [native code] }
Copy after login
Number Returns the text representation of the number.
String returns the value of the String object.
Default returns "<span style="font-family:NSimsun">[object objectname]</span>", where <span style="font-family:NSimsun">objectname</span> is the name of the object type.

valueOf() method: Returns the original value of the specified object.

Object Return Value
Array The elements of the array are converted to strings, these Strings are separated by commas and concatenated together. Its operation is the same as the Array.toString and Array.join methods.
Boolean Boolean value.
Date The time stored is the number of milliseconds since midnight on January 1, 1970 UTC.
Function The function itself.
Number Number value.
Object The object itself. This is the default.
String String value.

2. Common points and differences between the two:

Common points: In JavaScript, the toString() method and The valueOf() method is automatically called when outputting the object.

The difference: when the two coexist, in numerical operations, valueOf is called first, and in string operations, toString is called first.

Related recommendations]

1. Detailed explanation of valueOf method examples in java

2. Between valueOf and toString, (String) in Java The difference between

3.The difference between valueOf, parseInt and toString in Java

4. In-depth understanding of valueOf function and toString method

5. Introduction to ’s object conversion functions toString() and valueOf()

6. Use toString() method to return time as a string

source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn:Public welfare online PHP training,Help PHP learners grow quickly!