Possible Duplicate:
Split array into chunks
I am trying to convert an array of values into a new array of paired values.
For example i need to convert:
var arr = [1,2,3,4,5,6,7,8];
into:
arr = [[1,2], [3,4], [5,6], [7,8]];
I tried using jQuery's .map() method like so but this did not work for me:
arr= $.map(arr, function(n, i){
return [n + ',' + n[ i + 1 ]];
});
If you insist on using map, you could do it like this:
arr= $.map(arr, function(n, i){
if (i%2 === 0) return [[n, arr[ i + 1 ]]];
});
=== to compare with 0. And the use of {} (although not needed) is a nice way to write clean code.
If you don't want to use a hammer on a thumbtack:
var arr = [1,2,3,4,5,6,7,8];
var newarr = new Array();
for (var i=0; i<arr.length; i=i+2) {
newarr.push(arr.slice(i,i+2));
}
don't use jquery for every problem:
var arr = [1, 2, 3, 4, 5, 6, 7, 8];
var narr = [];
for (i = 0; i < arr.length; i = i + 2) {
narr[i / 2] = [arr[i], arr[i + 1]];
}
but this only works if you have an even count of arr
Another example...
var arr = [1 , 2, 3, 4, 5, 6, 7, 8]
var final = []
while(arr.length) {
final.push(arr.splice(0, 2))
}
splice() and I'm using slice(). Nice job.You don't want map, you want reduce.
Here is something that should work:
var endArr = [],
arr = [ 1, 2, 3, 4, 5, 6, 7, 8 ],
i = 0;
arr.reduce( function( prev, curr, index ) {
if ( index % 2 === 0 ) {
endArr[ i ] = [ prev, curr ];
}
i++;
} );
And just something else I thought about:
var endArr = [],
arr = [ 1, 2, 3, 4, 5, 6, 7, 8 ];
while ( arr.length ) {
endArr.push( arr.splice( 0, 2 ) );
}
Edit: Arf, it's the same solution as Chris Gutierrez.
mapwhen given an array as a return flattens it into the new array, you probably just want to do it yourself.[...].mapis a built-in function in javascript (ECMAScript 5th edition, supported by all modern browsers, unless you count the people who still haven't clicked the "upgrade to IE9" button that Microsoft shoves infront of you).