Javascript：将字符串拆分为数组匹配参数

Question

I have a string that has numbers and math operators ( + , x , - , / ) mixed in it

'12+345x6/789'

I need to convert it into an array seperated by those math operators.

[12, +, 345, x, 6, /, 789]

What is a simple way of doing this?

Answer 1

Splitting on consecutive non-digit chars \\D+ you get

 console.log ('12+345x6/789'.split (/\\D+/)) // [ '12', '345', '6', '789' ] 

If you add a capture group , (\\D+) you get the separator too

 console.log ('12+345x6/789'.split (/(\\D+)/)) // [ "12", "+", "345", "x", "6", "/", "789" ] 

If you want to support parsing decimals, change the regexp to /([^0-9.]+)/ - Note, \\D used above is equivalent to [^0-9] , so all we're doing here is adding . to the character class

 console.log ('12+3.4x5'.split (/([^0-9.]+)/)) // [ "12", "+", "3.4", "x", "5" ] 

And a possible way to write the rest of your program

 const cont = x => k => k (x) const infix = f => x => cont (f (x)) const apply = x => f => cont (f (x)) const identity = x => x const empty = Symbol () const evaluate = ([ token = empty, ...rest], then = cont (identity)) => { if (token === empty) { return then } else { switch (token) { case "+": return evaluate (rest, then (infix (x => y => x + y))) case "x": return evaluate (rest, then (infix (x => y => x * y))) case "/": return evaluate (rest, then (infix (x => y => x / y >> 0))) default: return evaluate (rest, then (apply (Number (token)))) } } } const parse = program => program.split (/(\\D+)/) const exec = program => evaluate (parse (program)) (console.log) exec ('') // 0 exec ('1') // 1 exec ('1+2') // 3 exec ('1+2+3') // 6 exec ('1+2+3x4') // 24 exec ('1+2+3x4/2') // 12 exec ('12+345x6/789') // 2 

Answer 2

If you are unconcerned with whitespace, all you need is

'12+345x6/78-9'.match(/\d+|[\+-\/x]/g);

which splits the string into numbers and the + , - , \\ , and x tokens.

 'use strict'; const tokens = '12+345x6/78-9'.match(/\\d+|[\\+-\\/x]/g); console.log(tokens); 

To handle whitespace, consider

'12+3 45 x6/78-9'.match(/\d|\d[\s\d]\d|[\+-\/x]/g);

which splits the string into numbers (optionally allowing whitespace as a digit separator within a single number) and + , - , \\ , and x .

 'use strict'; const tokens = '12+3 45 x6/78-9'.match(/\\d+\\s?\\d+|\\d+|[\\+-\\/x]/g); console.log(tokens); 

Answer 3

这将工作

 console.log('12+345x6/789'.match(/\\D+|\\d+/g))