The implementation of the enumeration obtains 1-1000 of all occurrences of 1 digits and calculates the number of 1 _javascript tips

Recently had the honor to get a small interview question, studied the research, then shares out, hoped can be helpful to everybody's code cause.

The interview question is: Get 1-1000 of all occurrences of 1, and calculate the number of 1

Solution:

Copy Code code as follows:

Enumeration method can only be viewed under Google Browser
(function () {
var tmp = [];
for (var i = 1; i< 1001; ++i) {
/1/g.test (' + i-1 ') && tmp.push (i);
}
Console.log (Tmp.length)

Console.log (Tmp.reduce function (i,j) {
Return i+j
}))

})()

The above is the implementation of the enumeration, but if you do not use it from the 1-n, because n is not necessarily how much.