Question

Let’s say I have this array

[1,2,3,4,5,6,7,9]

What I want to output is a string with:

"{1 to 7;9}" 

I have this code:

var _checkbox = [1,2,3,4,5,6,7,9];
for (i=0; i<_checkbox.length; i++) {
    //if ($($(_checkbox)[i]).is(":checked"))
       ignore_response_from.push(i+1)
}

The only problem I have is to output the string “{1 to 7;9}”. how should I do this?

Answer 1

Here you go, I have included a basic test case as well:

var tests = [
    [1,2,3,4,5,6,7,9],
    [1,2,3,4,5,6,7,12,13,14,15,16,20],
    [1,2,3,4,5,6,7,12,13,14,15,16,20,21,22,23],
    [1,2,3,4,5,6,7,120,13,14,15,16,2890,21,22,23],
    [1,2,3,4,8,9,10,11,12,14,16,18,20,21,22,23,30,31,34]
];

var processArray = function(arr, sep) {
    var l = arr.length, i, sl, res = [], succ = [];

    for (i = 0; i < l; i++) {
        var c = (i != 0 && (arr[i - 1] + 1 !== arr[i]));
        if ((i == l - 1) || c) {   
             if (!c) succ.push(arr[i]);

             if ((sl = succ.length) > 0) {
                 res.push(succ[0] + sep + succ[sl - 1]);
                 succ = [];
             } 

             if (arr[i + 1] - 1 === arr[i]) {
                 succ.push(arr[i])
             } else if (c) {
                 res.push(arr[i]);
             }
         } else {
             succ.push(arr[i]);                 
         }
    }

    return res;
}

// setup
for (var i = 0; i < tests.length; i++) {
    console.log('Test ' + i + ' : { ' + processArray(tests[i], ' to ').join('; ') + ' }');
}

here is the fiddle