How to get only Numbers from a string and store it in an Array using Javascript-CodePudding

I have a string that contains a mix of characters and numbers. I want to separate out the numbers from the string and store them in an Array. So far I have been able to separate the strings and numbers and put them in Array and then able to get only numbers but the string type data is NaN. I am unable to get rid of NaN values from the Array.

So far my code looks like this:

arrayList = "abcd_456_yasdb_382_h_83_2";
new_arrayList = arrayList.split('_');
console.log(new_arrayList); // Output : [ 'abcd', '456', 'yasdb', '382', 'h', '83', '2' ]


new_arrayList = new_arrayList.map(Number);
console.log(new_arrayList); // Output :  [ NaN, 456, NaN, 382, NaN, 83, 2 ]

onlyNumArray = []

for(i =0; i<new_arrayList.length; i  ) {
    // console.log(new_arrayList[i]);
    if(typeof (new_arrayList[i]) === "number" && typeof(new_arrayList[i]) != NaN) {
        onlyNumArray.push(new_arrayList[i])
    }
    else {
        console.log("Not a number")
    }
}
console.log(onlyNumArray)  // Output : [ NaN, 456, NaN, 382, NaN, 83, 2 ]

Output = [ NaN, 456, NaN, 382, NaN, 83, 2 ]
Expected Output = [456, 382,83,2]

CodePudding user response：

Is there a reason you can't use Array#filter? Also, you can't check for NaN by equality (except that NaN != NaN as Passerby points out). You have to use isNaN (or Number#isNaN).

const input = 'abcd_456_yasdb_382_h_83_2';

const tokens = input
  .split('_')
  .map(Number)
  .filter(i => !isNaN(i));

console.log(tokens);

CodePudding user response：

You could use the array.filter() method and do something like this :

const unfilteredArray = [ NaN, 456, NaN, 382, NaN, 83, 2 ]
const numbersArray = unfilteredArray.filter(Number)
// Output : [ 456, 382, 83, 2 ]

CodePudding user response：

const newArrayList = arrayList.split('_').filter(element => {
  return Number.parseInt(element);
}).map(element => {
  return Number.parseInt(element)
});

CodePudding user response：

input = 'abcd_456_yasdb_382_h_83_2';
array = [...input.matchAll(/\d /g)].map(a => parseInt(a[0]));

console.log(array); // [456, 382, 83, 2]