Download Document on click in Document Library

Default behavior in SharePoint is to open display view form on click to an item on document library , if you need to download document item instead of view it we need to have workaround .

in this example we only download documents with extensions ".doc,.docx,.xls,.xlsx,.ppt,.pptx,.pdf"

Follow steps below to change behavior to download document :
-  open document library and add content query web-part .
- Edit web-part as HTML.
- add the following code :

$(function () { 

var extensions = ".doc,.docx,.xls,.xlsx,.ppt,.pptx,.pdf";

    $(".srch-Title3 a").each(function () {

        var hrefDoc = $(this).attr('href');

        var fileExt = hrefDoc.substring(hrefDoc.lastIndexOf('.'), hrefDoc.length);

        if (extensions.toString().toLowerCase().indexOf(fileExt) != -1) {

            this.href = '/_layouts/download.aspx?SourceURL=' + this.href;

        }

    });

    $("a[onclick*='DispEx']").each(function (data) {

        var fileExtIndex = this.toString().lastIndexOf('.');

        var fileExt = this.toString().substr(fileExtIndex);

        var index = extensions.toString().indexOf(fileExt);

        if (extensions.toString().toLowerCase().indexOf(fileExt) != -1) {

            var href = this.href;

            this.href = '/_layouts/download.aspx?SourceURL=' + this.href;

            $("a[onclick*='DispEx']").removeAttr('onclick');

            $("a").removeAttr('onmousedown');

        }

    });

    $("a[onclick*='DispDocItemExWithServerRedirect']").each(function (data) {

        var fileExtIndex = this.toString().lastIndexOf('.');

        var fileExt = this.toString().substr(fileExtIndex);

        var index = extensions.toString().indexOf(fileExt);

        if (extensions.toString().toLowerCase().indexOf(fileExt) != -1) {

            var href = this.href;

            this.href = '/_layouts/download.aspx?SourceURL=' + this.href;

     $("a[onclick*='DispDocItemExWithServerRedirect']").removeAttr('onclick');

            $("a").removeAttr('onmousedown');    

                         }
                    });