jquery - Parse an integer (and *only* an integer) in JavaScript -

prompt possible translate string number variant except integer produced error.

func('17') = 17; func('17.25') = nan func(' 17') = nan func('17test') = nan func('') = nan func('1e2') = nan func('0x12') = nan 

parseint not work, because not work correctly.

parseint('17') = 17; parseint('17.25') = 17 // incorrect parseint(' 17') = nan parseint('17test') = 17 // incorrect parseint('') = nan parseint('1e2') = 1 // incorrect 

and importantly: function work in ie, chrome , other browsers!!!

you can use regular expression , ternary operator reject strings containing non-digits:

function intornan (x) {    return /^\d+$/.test(x) ? +x : nan  }    console.log([    '17', //=> 17    '17.25', //=> nan    ' 17', //=> nan    '17test', //=> nan    '', //=> nan    '1e2', //=> nan    '0x12' //=> nan  ].map(intornan))