{"id":570,"date":"2022-08-30T15:03:33","date_gmt":"2022-08-30T15:03:33","guid":{"rendered":"https:\/\/unknownerror.org\/index.php\/2013\/11\/09\/how-to-check-if-a-number-is-float-or-integer-collection-of-common-programming-errors\/"},"modified":"2022-08-30T15:03:33","modified_gmt":"2022-08-30T15:03:33","slug":"how-to-check-if-a-number-is-float-or-integer-collection-of-common-programming-errors","status":"publish","type":"post","link":"https:\/\/unknownerror.org\/index.php\/2022\/08\/30\/how-to-check-if-a-number-is-float-or-integer-collection-of-common-programming-errors\/","title":{"rendered":"How to check if a number is float or integer?-Collection of common programming errors"},"content":{"rendered":"

how to find if a number is float or integer?<\/p>\n

1.25 --> float  \n1 --> integer  \n0 --> integer  \n0.25 --> float\n<\/code><\/pre>\n
    \n
  1. \n
    check a remainder when dividing by 1:<\/p>\n
    function isInt(n) {\n   return n % 1 === 0;\n}\n<\/code><\/pre>\n
    If you don’t know that the argument is a number-<\/p>\n
    function isInt(n) {\n   return typeof n === 'number' && n % 1 == 0;\n}\n<\/code><\/pre>\n
    If you also want to include examples such as 1E308 is a float, and not an integer:<\/p>\n
    function isInt(n) {\n   return typeof n === 'number' && parseFloat(n) == parseInt(n, 10) && !isNaN(n);\n} \/\/ 6 characters\n<\/code><\/pre>\n<\/li>\n
  2. \n
    Try this.<\/p>\n
    function isFloat (n) {\n  return n===+n && n!==(n|0);\n}\n\nfunction isInteger (n) {\n  return n===+n && n===(n|0);\n}\n<\/code><\/pre>\n<\/li>\n
  3. \n
    Here are efficient functions that check if the value is a number or can be safely converted to<\/em> a number:<\/p>\n
    function isNumber(value) {\n    if ((undefined === value) || (null === value)) {\n        return false;\n    }\n    if (typeof value == 'number') {\n        return true;\n    }\n    return !isNaN(value - 0);\n}\n<\/code><\/pre>\n
    And for integers (would return false if the value is a float):<\/p>\n
    function isInteger(value) {\n    if ((undefined === value) || (null === value)) {\n        return false;\n    }\n    return value % 1 == 0;\n}\n<\/code><\/pre>\n
    The efficiency here is that parseInt (or parseNumber) are avoided when the value already is a number. Both parsing functions always<\/em> convert to string first and then attempt to parse that string, which would be a waste if the value already is a number.<\/p>\n
    Thank you to the other posts here for providing further ideas for optimization!<\/p>\n<\/li>\n
  4. \n
    You can use a simple regular expression:<\/p>\n
    function isInt(value)\n{\n    var er = \/^[0-9]+$\/;\n\n    return ( er.test(value) ) ? true : false;\n}\n<\/code><\/pre>\n
    Or you can use the below functions too, according your needs. They are developed by the PHPJS Project.<\/p>\n
    is_int()<\/code> => Check if the variable type is Integer and if its content is Integer<\/p>\n
    is_float()<\/code> => Check if the variable type is Float and if its content is Integer<\/p>\n
    ctype_digit()<\/code> => Check if the variable type is String and if its content has only decimal digits<\/p>\n<\/li>\n
  5. \n
    Why not something like this:<\/p>\n
    var isInt = function(n) { return parseInt(n) === n };\n<\/code><\/pre>\n<\/li>\n
  6. \n
    It really depends on what you want to achieve. If you want to “emulate” strongly typed languages then I suggest you not trying. As others mentioned all numbers have the same representation (the same type).<\/p>\n
    Using something like Claudiu<\/em> provided:<\/p>\n
    isInteger( 1.0 )<\/code> -> true<\/p>\n
    which looks fine for common sense, but in something like C you would get false<\/code><\/p>\n<\/li>\n
  7. \n
    As others mentioned, you only have doubles in JS. So how do you define a number being an integer? Just check if the rounded number is equal to itself:<\/p>\n
    function isInteger(f) {\n    return typeof(f)===\"number\" && Math.round(f) == f;\n}\nfunction isFloat(f) { return typeof(f)===\"number\" && !isInteger(f); }\n<\/code><\/pre>\n<\/li>\n
  8. \n
    THIS IS FINAL CODE FOR CHECK BOTH INT AND FLOAT<\/p>\n
    function isInt(n) { \n   if(typeof n == 'number' && Math.Round(n) % 1 == 0) {\n       return true;\n   } else {\n       return false;\n   }\n} \n<\/code><\/pre>\n
    OR<\/p>\n
    function isInt(n) {   \n   return typeof n == 'number' && Math.Round(n) % 1 == 0;   \n}   \n<\/code><\/pre>\n<\/li>\n
  9. \n
    function isInteger(n) {\n   return ((typeof n==='number')&&(n%1===0));\n}\n\nfunction isFloat(n) {\n   return ((typeof n==='number')&&(n%1!==0));\n}\n\nfunction isNumber(n) {\n   return (typeof n==='number');\n}\n<\/code><\/pre>\n<\/li>\n
  10. \n
    function isInt(n) \n{\n    return n != \"\" && !isNaN(n) && Math.round(n) == n;\n}\nfunction isFloat(n){\n    return n != \"\" && !isNaN(n) && Math.round(n) != n;\n}\n<\/code><\/pre>\n
    works for all cases.<\/p>\n<\/li>\n
  11. \n
    Another method is:<\/p>\n
        function isFloat(float) {\n        return \/\\.\/.test(float.toString());\n    }\n<\/code><\/pre>\n
    Might not be as efficient as the others but another method all the same.<\/p>\n<\/li>\n
  12. \n
    !!(24%1) \/\/ false\n!!(24.2%1) \/\/ true\n<\/code><\/pre>\n<\/li>\n
  13. \n
    For integers I use this<\/p>\n
    function integer_or_null(value) {\n    if ((undefined === value) || (null === value)) {\n        return null;\n    }\n    if(value % 1 != 0) {\n        return null;\n    }\n    return value;\n}\n<\/code><\/pre>\n<\/li>\n
  14. \n
    It really doesn’t have to be so complicated. The numeric value of an integer’s parseFloat() and parseInt() equivalents will be the same. Thus you can do like so:<\/p>\n
    function isInt(value){ \n    return (parseFloat(value) == parseInt(value)) && !isNaN(value);\n}\n<\/code><\/pre>\n
    Then<\/p>\n
    if (isInt(x)) \/\/ do work\n<\/code><\/pre>\n
    This will also allow for string checks and thus is not strict. If want a strong type solution (aka, wont work with strings):<\/p>\n
    function is_int(value){ return !isNaN(parseInt(value * 1) }\n<\/code><\/pre>\n<\/li>\n
  15. \n
    In java script all the numbers are internally 64 bit floating point<\/code>, same as double in java. There are no diffrent types in javascript, all are represented by type number<\/code>. Hence you wil l not be able make a instanceof<\/code> check. However u can use the above solutions given to find out if it is a fractional number. designers of java script felt with a single type they can avoid numerous type cast errors.<\/p>\n<\/li>\n
  16. \n
    float<\/code> values consists of .<\/code>, so here we can use indexOf<\/code> method.<\/p>\n
    function isInt(number){\n    if(number.toString().indexOf(\".\") > -1)\n        return false; \/\/ it is float\n    else \n        return true; \/\/it is integer\n}  \n<\/code><\/pre>\n
    The above code is only applicable if the given variable is number<\/code>. if you are not sure about the type of variable , then do the following before the above code:<\/p>\n
    \/\/as suggested by @kennebec\nfunction isNumber(number){\n    return typeof n === 'number'\n}\n<\/code><\/pre>\n<\/li>\n
  17. \n
    Any Float number with a zero decimal part (e.g. 1.0, 12.00, 0.0) are implicitly cast to Integer, so it is not possible to check if they are Float or not.<\/p>\n<\/li>\n
  18. \n
    Here’s what I use for integers:<\/p>\n
    Math.ceil(parseFloat(val)) === val\n<\/code><\/pre>\n
    Short, nice \ud83d\ude42 Works all the time. This is what David Flanagan suggests if I’m not mistaken.<\/p>\n<\/li>\n
  19. \n
    parseInt(yourNumber)=== parseFloat(yourNumber)\n<\/code><\/pre>\n<\/li>\n<\/ol>\n
    Originally posted 2013-11-09 21:01:54. <\/small><\/p>","protected":false},"excerpt":{"rendered":"
    how to find if a number is float or integer? 1.25 –> float 1 –> integer 0 –> integer 0.25 –> float check a remainder when dividing by 1: function isInt(n) { return n % 1 === 0; } If you don’t know that the argument is a number- function isInt(n) { return typeof n […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-570","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/570","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/comments?post=570"}],"version-history":[{"count":0,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/570\/revisions"}],"wp:attachment":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/media?parent=570"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/categories?post=570"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/tags?post=570"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}