In-depth understanding of JS regular expression range class analysis
This article mainly introduces the analysis of range classes for in-depth understanding of JS regular expressions. It has certain reference value. Now I share it with you. Friends in need can refer to it
Range classes
When using regular expressions, many times we want to match all letters from a~z. Many people think of using the character class [abcdefg...z]
, however, this method requires entering all the letters that need to be matched. So, is there a simpler way?
Fortunately, regular expressions provide a range class, which allows us to use [a-z]
to connect two characters to represent any character from a to z.
Basic usage
let text = 'a1b2d3x4z5' let reg = /[a-z]/g text.replace(reg, 'Q') // Q1Q2Q3Q4Q5
tips: It is worth noting that the range class is a closed interval, that is: [a-z]
includes a and z
range Concatenation of classes
There is a little trick when using range classes: you can concatenate within a class composed of []
, for example: [a-zA-Z]
let text = 'a1B2d3X4Z5' let reg = /[a-zA-Z]/g text.replace(reg, 'Q') // Q1Q2Q3Q4Q5
The above is the entire content of this article. I hope it will be helpful to everyone's study. For more related content, please pay attention to the PHP Chinese website!
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In-depth understanding of metacharacters and character class analysis of JS regular expressions
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