What is the correct way to convert value of String variable to int/numeric variable? Why is bcInt still string and why does isNaN return true?
bc=localStorage.getItem('bc');
var bcInt=parseInt(bc,10);
var bcInt2=1;
console.log("bc------------>" +bc +" isNaN:" +isNaN(bc)); //isNaN returns true
console.log("bcInt------------>" +bcInt +" isNaN:" +isNaN(bcInt)); //isNaN returns true
bcInt2// isNaN returns false
parseInt returns a number only if you pass it a number as first character.
Examples:
parseInt( 'a', 10 ); // NaN
parseInt( 'a10', 10 ); // NaN
parseInt( '10a', 10 ); // 10
parseInt( '', 10 ); // NaN
parseInt( '10', 10 ); // 10
Also, you may take a look at the + operator if you want to get strings that are only numbers.
+'a'; // NaN
+'a10'; // NaN
+'10a'; // NaN
+''; // 0, that's tricky
+'10'; // 10
Edit: According to your comment, I've tested parseInt:
parseInt( '08-20 19:41:02.880', 10 ); // 8
You're doing something else wrong. parseInt returns everything till it's not a number. If the first isn't a number (or it doesn't find any number), it returns NaN.
let no = "25";
typeof no 'string'
let no2 = parseInt(no); no2 25
typeof no2 'number'
The answer is that I used localStorage.setItem('bc',JSON.stringify(bc)) and it added double quote to bc because it was in that case already a string and that's why parseInt wasn't working. Value was ""1"".
parseInt()returns aNaN, then your string doesn't actually contain a numeric representation of a value. If you had told us what the value of "bc" is, then perhaps somebody could help, but you failed to do that. That value is of course the key to the whole problem.bc? If it is not a number (empty, got alpha characters etc...), that's what I would expect to see.1then it's not going to work.