When looping through an array I wish to push the elements to a new array. That array however remains empty

Question

When I run this loop it takes in an array which contains eight numbers, it loops through and simply pushes them to a global array which is named results. For some reason when I console.log this array outside of the loop it returns 0 []. I wish it to return the eight numbers from the other array.

const results = []

const validate = arr => {
  for(let i = 0; i < arr.length; i++){
    results.push(arr[i])
  }

}
console.log(results)

Answer 1

What you have done here is simply define a function that copies the contents of the array that has been passed into it. You need to call the function validate with the appropriate value.

const results = []

const validate = arr => {
  for(let i = 0; i < arr.length; i++){
    results.push(arr[i])
  }

}
validate([1,2,3,4,5,6,7,8]);
console.log(results);

Answer 2

That is because you have to run the function validate, now you are just printing results[] which has no items.

validate(arr);

const results = []
const arr = [1, 2, 3, 4, 5, 6, 7, 8];
const validate = arr => {
  for (let i = 0; i < arr.length; i++) {
    results.push(arr[i])
  }

}
validate(arr);
console.log(results);

But if you want to make a copy, you can just use:

const arr = [1, 2, 3, 4, 5, 6, 7, 8];
const results = [...arr];
console.log(results);

Answer 3

You missed calling the function.

const arr = [1, 2, 3, 4, 5, 6, 7, 8];
const result = [];
arr.map((num) => result.push(num));
console.log(result);

Answer 4

const results = []
const validate = (arr) => {
    console.log(arr)
    arr.forEach((value)=>{
        results.push(value)
    });
}

validate([1,2,3,4,5,6,7,8]);
console.log(results);

Answer 5

You might use regular expression for this as follows

import pandas as pd
df = pd.DataFrame({"street":["Main Street","Jon Smith Close","The Rovers Avenue"]})
df2 = df.street.str.extract(r"(?P<Beginning>.+)\s(?P<Ending>\S+)")
df = pd.concat([df,df2],axis=1)
print(df)

output

              street   Beginning  Ending
0        Main Street        Main  Street
1    Jon Smith Close   Jon Smith   Close
2  The Rovers Avenue  The Rovers  Avenue

Explanation: I used named capturing group which result in pandas.DataFrame with such named columns, which I then concat with original df with axis=1. In pattern I used group are sheared by single whitespace (\s), in group Beginning any character is allowed in group Ending only non-whitespace (\S) characters are allowed.