问执行"...used超出作用域“。KSLint中的错误是否导致'[1]为null或不是对象‘错误？

EN

// Make current view actively selected in view dropdown button.
    var classes = $('body').attr( 'class' ).split( ' ' );
    for ( i in classes ) {
        // Extract current view from the body class.
        var matches = /ai1ec-action-([\w]+)/.exec( classes[i] );
        if ( matches != null ) break;
    }
    // Get the dropdown menu link of the active view.
    var $selected_view = $( '#ai1ec-view-' + matches[1] );
    // Replace contents of dropdown button with menu link, plus the caret.
    $( '#ai1ec-current-view' )
        .contents()
            .remove()
            .end()
        .prepend( $selected_view.contents().clone() )
        .append( '<span class="caret"></span>' );
    // Deactivate all dropdown menu items.
    $( '#ai1ec-view-dropdown .dropdown-menu li' ).removeClass( 'active' );
    // Activate only currently selected dropdown menu item.
    $selected_view.parent().addClass( 'active' );