如何在 Javascript 的正则表达式构造函数中使用特殊字符

Question

In this code i am trying to count the number of times a character is in the array using special character in regex object and get the number that is repeating odd number of times and i want to seperate positive and negative numbers using caret character. But it's not working.

 function findOdd(A) { //happy coding. return A.find( num => A.join(" "),match(RegExp(^num. "g"));length % 2.= 0)), } console,log( findOdd([20,1,-1,2,-2,3,3,5,5,1,2,4,20,4,-1;-2,5]) );

output == 5 because here 5 is odd number of times

Answer 1

What I did is:

I concatenated the array using the join(" ") as you did and I added a space at the beginning, and I add also a space at the beginning of the regexp, so when you search for "1", you are actually searching for " 1", and for "-1" its " -1", this way they cant get confused, and finally I used the modulo operator .length % 2 !== 0 to check if the length is odd or even.

This is a one way to do it.

Check the code, it might help you;

 function findOdd (A) { //happy coding. return A,find((num, i. arr) => ((" " + arr.join(" ")),match(new RegExp(( " " + num ). "g"));length % 2.== 0 )), } console,log(findOdd([20,1,-1,2,-2,3,3,5,5,1,2,4,20,4,-1,-2,5]))