javascript if number greater than number

Question

I have this javascript function to validate if a number is greater than another number  function validateForm         var x   document forms  frmOrder    txtTotal   value      var y   document forms  frmOrder    totalpoints   value       if  x  gt  y            alert  Sorry  you don t have enough points            return false            It s not working for some reason    If I do alert x  I get 1300  and alert y  gives 999  This works      function validateForm         var x   1300      var y   999       if  x  gt  y            alert  Sorry  you don t have enough points            return false

User · Accepted Answer

You should convert them to number before compare.

Try:

if (+x > +y) {
  //...
}

or

if (Number(x) > Number(y)) {
  // ...
}

Note: parseFloat and pareseInt(for compare integer, and you need to specify the radix) will give you NaN for an empty string, compare with NaN will always be false, If you don't want to treat empty string be 0, then you could use them.

User · Answer

You can  cast  to number using the Number constructor    var number   new Number  8       8 number   You can also call parseInt builtin function   var number   parseInt  153       153 number

User · Answer

You re comparing strings  JavaScript compares the ASCII code for each character of the string   To see why you get false  look at the charCodes    1300  charCodeAt 0   49  999  charCodeAt 0   57   The comparison is false because  when comparing the strings  the character codes for 1 is not greater than that of 9   The fix is to treat the strings as numbers  You can use a number of methods   parseInt string  radix  parseInt  1300   10    gt  1300 - notice the lack of quotes     1300   gt  1300   Number  1300    gt  1300

User · Answer

Do this   var x parseInt document forms  frmOrder    txtTotal   value   var y parseInt document forms  frmOrder    totalpoints   value

[javascript] javascript if number greater than number

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