No more nonsense, direct hair results.
In JS, the whole string substitution can be in the following ways:
Str.replace (/string/g to be replaced, "new string")
Like what:
"Yyyy-mm-dd-hh-mm-ss". Replace (/-/g, "/")
The results are as follows:
"Yyyy/mm/dd/hh/mm/ss"
Principle See JavaScript Replace () method introduction
Definition and usage
The replace () method is used to replace other characters with some characters in a string, or to replace a substring that matches a regular expression.
Grammar
Stringobject.replace (regexp/substr,replacement)
Parameters |
Description |
Regexp/substr |
Necessary. A RegExp object that specifies the substring or pattern to replace. Note that if the value is a string, it is used as the direct volume text pattern to be retrieved, instead of being converted to the RegExp object first. |
Replacement |
Necessary. A string value. A function that specifies replacement text or generates alternate text. |
return value
A new string that is obtained after the first match or all matches of regexp have been replaced with replacement .
Description
The replace () method of the string Stringobject performs a find-and-replace operation. It looks for substrings in Stringobject that match regexp, and then replaces them with replacement . If RegExp has global flag G, then the Replace () method replaces all matching substrings. Otherwise, it replaces only the first matched substring.
replacement can be a string, or it can be a function. If it is a string, then each match is replaced by a string. However, the $ character in replacement has a specific meaning. As shown in the following table, it shows that the resulting string from a pattern match will be used for substitution.
character |
Replace text |
$, $ 、...、 |
The text that matches the 1th to 99th sub-expression in RegExp. |
$& |
A substring that matches the regexp. |
$` |
The text that is located to the left of the matching substring. |
$ |
The text on the right side of the matching substring. |
$$ |
Direct volume symbol. |
Note: ECMAScript v3 stipulates that the parameter replacement of the replace () method can be a function instead of a string. In this case, each match calls the function, and the string it returns is used as the replacement text. The first parameter of the function is a string that matches the pattern. The next parameter is a string that matches the subexpression in the pattern and can have 0 or more of these parameters. The next argument is an integer that declares where the match appears in the Stringobject. The last parameter is the stringobject itself.
JS string Replacement Reference: http://www.w3school.com.cn/jsref/jsref_replace.asp
JS Regular use reference: http://www.w3school.com.cn/jsref/jsref_obj_regexp.asp
Original address: https://www.cnblogs.com/cblogs/p/9293522.html
Reprint Annotated Source
All the strings in JS are replaced