html - Using a textbox to take in an integer value for use in Javascript function. Is there a simpler way? -

html - Using a textbox to take in an integer value for use in Javascript function. Is there a simpler way? -

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convert string number in javascript 4 answers

i'm making simple calculator utilize in intro javascript lesson. know if there's simpler way of taking value html input textbox integer having utilize javascript parse() method?

html:

<input type = "text" id="num1">

js:

var num1 = parseint(document.getelementbyid("num1").value);

you can forcefulness string 32-bit integer this:

var num1 = ~~document.getelementbyid("num1").value;

you can, alternatively, take number possible fractional part with

var num1 = +document.getelementbyid("num1").value;

in both cases, can check see if original string did number using isnan():

if (isnan(num1)) { // bad input }

javascript html parsing