Why code returns output + undefined?
A function, where argument h is equal 680131659347. Output is leepadgdenifednu. It's leepadg + denifednu (undefined).
var f = function (h) {
var letters, result, i;
i = 7;
letters = "acdegilmnoprstuw";
while (i) {
result += letters[parseInt(h % 37)];
h = h / 37;
i--;
}
return result.split("").reverse().join("");
};
You need to initialize the value of result, when you way var result, result will have a value of undefined then when you use it in a string concatenation the value will be undefined+<concatenated value>
var log = (function() {
var $log = $('#log');
return function(msg) {
$('<p/>', {
text: msg
}).prependTo($log)
}
})();
var f = function(h) {
var letters, result = '',
i;
i = 7;
letters = "acdegilmnoprstuw";
while (i) {
result += letters[parseInt(h % 37)];
h = h / 37;
i--;
}
return result.split("").reverse().join("");
};
log(f(680131659347))<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div id="log"></div>You were Not Initialize the Result and You are Try to Concate the value to result
var f = function (h) {
var letters, result, i;
result=//Initialize Result
i = 7;
letters = "acdegilmnoprstuw";
while (i) {
result += letters[parseInt(h % 37)];
h = h / 37;
i--;
}
return result.split("").reverse().join("");
};
use this:
var f = function (h) {
var letters, result, i;
i = 7;
letters = "acdegilmnoprstuw";
result="";// initailize result
while (i) {
result += letters[parseInt(h % 37)];
h = h / 37;
i--;
}
return result.split("").reverse().join("");
};
result is not initialized as string so very first time of concatenation its generate an error like undefined then its ok , so initialize the result variable as result=''
var f = function (h) {
var letters, result='', i;
i = 7;
letters = "acdegilmnoprstuw";
while (i) {
result += letters[parseInt(h % 37)];
h = h / 37;
i--;
}
return result.split("").reverse().join("");
};
leepadgdenifednu, so it works fine, I supposeleepadgdenifednuit'sleepadg+denifednu(undefined)resultan initial value to concatenate onto --var letters, result = '', i;.