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问题 I have a json-object, which I print to the screen (using alert()-function): alert(object); Here is the result: Then I want to print the value of the id to the screen: alert(object["id"]); The result is this: As you can see, the value of key "id" is not(!!!) undefined. What the hell is going on here?! 回答1: Looks like your json object is not really an object, it's a json string. in order to use it as an object you will need to use a deserialization function like JSON.parse(obj) . Many

问题 I'm having a real problem with JavaScript scope in IE 9. This is inside the body of my document (yes, I realize script should go in the head for proper HTML, but I've never had it break a script before). The script is in the body because I don't want to mess with a shared header page for a script that is only relevant for this page: <script type="text/javascript"> function googleMapsQuery(accountNum) { // function code is here (omitted for brevity) } </script> This is inside a td block inside

问题 I have a problem with caling the getResources() function in an standard class. All imports must be there to use the function. Is there any special class I need to extend my class? Thanks for the immediate help. package com.example.helloandroid; import android.app.Activity; import android.content.ContentValues; import android.content.Context; import android.content.ContextWrapper; import android.content.res.Resources; import android.content.Intent; import android.os.Bundle; //import android

问题 Hi I'm getting following error and so far not able to fix it. Undefined symbols for architecture x86_64: "_OBJC_CLASS_$_GAI", referenced from: objc-class-ref in AppDelegate.o objc-class-ref in HomeViewController.o "_OBJC_CLASS_$_GAITrackedViewController", referenced from: _OBJC_CLASS_$_HomeViewController in HomeViewController.o "_OBJC_METACLASS_$_GAITrackedViewController", referenced from: _OBJC_METACLASS_$_HomeViewController in HomeViewController.o ld: symbol(s) not found for architecture

问题 I am trying to use React Navigation and StackNavigator to navigate around my app. I have a button with onPress={() => navigate('DetailsScreen') , and I was hoping that would take me to the DetailsScreen , but I'm getting the following error: E ReactNativeJS: undefined is not an object (evaluating 'this.props.navigation.navigate') What do I need to add in order to get this working? See my code here: https://gist.github.com/chapeljuice/bef4b0a4dedef2994c81f3634b81aa43 回答1: You component is not

问题 I'm trying to create a sass mixin for transitions. This is what I have so far. @mixin transition($var) -webkit-transition: $var transition: $var I want to be able to pass it multiple arguments like this @include transition(color .5s linear, width .5s linear) Unfortunately, I get the following error Syntax error: Mixin transition takes 1 argument but 2 were passed. Is there a way to do this so it produces the following output in css while still accepting an undefined number of arguments?

问题 Having real trouble figuring out where i'm going wrong on this one. Building a system using WEKA in java to study associations and am trying to implement the Apriori algorithm. Currently this is the code: package model; import weka.associations.*; import weka.core.Instances; import weka.core.converters.ConverterUtils.DataSource; public class Apriori { public static void main(String args[]) throws Exception { String dataset = "/Users/andrew/workspace/Movies/src/data/tagsfinal.arff"; DataSource

问题 This has got to be something simple. I searched the internet and only found syntax errors as the cause of this problem, but I can't find a syntax error. Here's the javascript : <script type="text/javascript" src="http://localhost/acrilart/javascript/jquery-1.6.4.min.js"></script> <script type="text/javascript"> $(document).ready(function(){ function hi(){ alert('hi'); } hi(); }); </script> And the HTML : <input type="text" name="cep" value="" id="cep" class="required cep field" onChange="hi()

问题 In IE, I can go like: var x = document.getElementById("header"); alert(x.all[0].tagName); If I try that in Firefox, I get the error "all is undefined". What is the Firefox equivalent of IE's .all property? 回答1: .all is a Microsoft-specific extension to the DOM, and is not supported by any other browsers (except Opera, I believe, who simulate it in order to improve compatibility with sites written for IE). You can use things like x.children and x.childNodes , or x.getElementById() and x

问题 I am getting a strange error message with the following piece of PHP code (I am not a PHP expert): if ( $file_loc != NULL ) { if ( file_exists($file_loc) ) { printf(" file exists"); $handle = fopen($file_loc, "rb"); $contents = fread($handle, filesize($file_loc)); fclose($handle); $result = gzdecode($contents); } } I am basically trying to load text content from a gzipped file. I get the following error: Fatal error: Call to undefined function gzdecode() in ...\sites\MyScripts\fw2.php on line