I want to convert an array from
arr = ["step","0","instruction","1"]
to
newArr = ["step",0,"instruction",1]
here is my sample code:
newArr = arr.map((x) => {
if (typeof x === "number") {
return x;
}
});
3 Answers
You could check if the string is convertable to a finite number and map the number in this case.
const
data = ["step", "0", "instruction", "1"],
result = data.map(v => isFinite(v) ? +v : v);
console.log(result);If you need all other numbers as well, you could convert to number and check the the string of is against the value.
const
data = ["step", "0", "instruction", "1", "NaN", "Infinity"],
result = data.map(v => v === (+v).toString() ? +v : v);
console.log(result);3 Comments
Andreas
And this is the first time someone asks such a question? Convert some "numbers" in an array into actual numbers?
Flashtube
Nope, see this post here: stackoverflow.com/questions/1133770/… . In That post however they don't account for the fact that not each value in the array is a number.
Nina Scholz
the problem is not the conversion, but the check if it is possible.
I think you are looking for something like this:
// Defining initial values
const initialValues = ["step","0","instruction","1"]
// Mapping initial values to a new parsed array
const parsedValues = initialValues.map(value => {
// We try to parse the value. If it isNaN (Not a number) we just return the value e.g. don't change it
if(isNaN(parseInt(value))) return value;
// Else the value can be parsed to a number, so we return the parsed version.
return parseInt(value);
})
// Printing the parsed results
console.log(parsedValues);
Comments
try this:
const arr = ["step","0","instruction","1"]
const newArray = arr.map(value => { //Iterate the array searching for possible numbers.
/* Check with function isNaN if the value is a number,
if true just return the value converted to number,
otherwise just return the value without modification */
if (!Number.isNaN(Number(value))) {
return Number(value)
}
return value
})
.map()then.map()is the wrong tool.