preg_match_all JS等价？

Question

在Javascript中是否有相当于PHP的preg_match_all？如果没有，那么将正则表达式的所有匹配项放入数组的最佳方法是什么？我愿意使用任何JS库来使它更容易。

Answer 1

您可以将match与全局修饰符一起使用：

>>> '1 2 3 4'.match(/\d/g);
["1", "2", "3", "4"]

Answer 2

John Resig在他的博客上写了一篇名为“Search and dont replace”

的伟大技巧

它使用javascript的replace函数，它接受一个回调函数，并且不返回任何内容以保持原始内容不变。

这可能比使用全局匹配并迭代结果数组更简洁，特别是如果你捕获了几个组。

Answer 3

JS中PHP的preg_match_all更好的等价物是使用exec（）函数。这将允许您捕获组，匹配（）您不能这样做。

例如，您希望捕获变量myString的所有时间和括号中的数字：

var myString = "10:30 am (15 left)11:00 am (15 left)11:30 am";
var pattern = /(\d{1,2}:\d{1,2}\s?[ap]m)\s\((\d+)/gi;
var match;
while (match = pattern.exec(myString)){
  console.log('Match: "' + match[0] + '" first group: -> "' + match[1] + '" second group -> ' + match[2]);
}

输出将是：

Match: "10:30 am (15" first group: -> "10:30 am" second group -> 15
Match: "11:00 am (15" first group: -> "11:00 am" second group -> 15

Answer 4

使用elapsed = MainCode()

import random
import string
import multiprocessing
import os
import sys
import time

if __name__ == "__main__":
    lines_wanted = input("input how many lines: ") #user can input how many lines he wants
    length = input("How long: ") #user can enter how long each line should be

def MainCode(lines_wanted, length):
    global elapsed
    elapsed = 0.0
    starttime = time.time() # start the time
    file = open("blablabla.txt", "a",) # open/create the file
    i = 0
    while 1 == 1:
        file.write(''.join(random.choice(string.ascii_letters + string.digits + ".") for i in range(int(length))) + "\n") # write the randomly generated lowercase string
        i += 1 * multiprocessing.cpu_count() # count how many lines the loop is on
        if i >= int(lines_wanted): # If it reaches the lines it would stop writing
            endtime = time.time() # stop the time
            elapsed = endtime - starttime #calculate the time
            return elapsed
            break

processes = []
if __name__ == '__main__':
    for _ in range(multiprocessing.cpu_count()):
        p = multiprocessing.Process(target=MainCode, args=(lines_wanted, length))
        p.start()
        processes.append(p)

    for process in processes:
        process.join()

elapsee = MainCode()

if __name__ == "__main__": # Prints this after finshing the func above
    print(f"Finished Writting {lines_wanted} lines, took {elapsee:.1f} to generate")