parse Float

Turn text that has just number characters into a floating point number value.


You can change a text string having number characters into an actual floating point value. The text needs to have only number characters. This can also include the '-' and the '.' symbols though.

If the text has other characters, like "-5.8g5u7", only -5.8 is returned since it is the best attempt at converting to a number. So, try not to mix number characters with letters or other symbols.

Powers of 10

If the text string has the letter ‘e’ after the number characters and then some more number characters like “2e4”, then the number characters after the ‘e’ are an exponent of 10. This means that a string with "7.5e2" becomes the value of 750 when converted to a floating point number. This is because the 2 after the e is 2 powers of ten which is 10 * 10 or 100. The resulting value then is 7.5 * 100 which equals 750.


  • a floating point number value for the text number in the string.


Take the first few digits of PI from the sentence and turn it into a number.

let text = "pi is 3.14...";
let pi = parseFloat(text.substr(6, 3));

See also

parse int