callback.call不是一個函數

Question

我收到此錯誤，並且很難糾正它。 我收到以下錯誤消息：callback.call不是函數

我在下面發布了代碼片段以進行評論，似乎當調用validateCheckBox（o）時會觸發錯誤。 我知道該錯誤是由於某個函數不在上下文中觸發的，但不確定如何解決。

function checkLength( o, n, min, max ) {
    console.log( arguments.length );
    if ( arguments.length < 4 ) {   
        // issue here with callback.call is not a function
        if ( validateCheckBox(o) ){
            validateCheckBox(o);  
        }
    }else {
        if ( o.val().length > max || o.val().length < min ) {
        o.addClass( "ui-state-error" );
        updateTips( "Length of " + n + " must be between " +
          min + " and " + max + "." );
        return false;
      } else {
        return true;
      }

    }

}

function validateCheckBox( o ) {

    var css = $(".border").css({
                                "border-color": "",
                                "border-weight": "",
                                "border-style" : "",
                                "background-color": "",
                                "background-image": "",
                                "background-repeat":"",
                                "background-position":""
                            });
    //console.log(css);
    var invalidChkBox = {   
                        "border-color":"#cd0a0a",
                        "border-weight":"1px",
                        "border-style":"solid",
                        "background-color": "#feflec",
                        "background-image": "url('lib/jquery-ui/css/images/ui-bg_glass_95_fef1ec_1x400.png')",
                        "background-repeat": "repeat-x",
                        "background-position": "50% 50%"


            }

    // throwing error callback is not defined
    var isChecked = $( "#verification" ).is(":checked");

    if ( isChecked == false || isChecked == undefined ) {

        $( ".border"  ).css( invalidChkBox );
        o.addClass( "ui-state-error" );
        $( ".validateTips" ).text( "You must agree that all information is accurate and true, by checking the box." );

    }else{
        // reported bug callback.call is not a function @error below
        $( ".validateTips" ).css( 'display', null ).text( "" );
        $( ".border"  ).css( css );



    }


}

 valid = valid && checkLength ( verification, "Verification", 1 );

提前致謝。

Answer 1

謝謝您的幫助。 事實證明這很簡單。 我試圖將CSS規則分配給具有已在其上定義的規則的類...

var css = $(".border").css({
                                "border-color": "",
                                "border-weight": "",
                                "border-style" : "",
                                "background-color": "",
                                "background-image": "",
                                "background-repeat":"",
                                "background-position":""
                            });
$( ".border"  ).css( css ); --> line throwing error.... 

Answer 2

根據您的評論，問題可能是checkLength的第一個參數是字符串而不是JQuery對象。 看起來電話應該更像

checkLength($("#first_name"), "First name", 3, 30 );

注意$("#first_name")會通過JQuery對象傳遞，該對象代表ID為#first_name的元素，而不僅僅是字符串"#first_name" 。