英文:
ERROR TypeError: undefined is not a function Why my object is not converting to array?
问题
ERROR TypeError: undefined is not a function 为什么我的对象无法转换为数组？这是我面临的错误，我试图映射当前为对象的所有项目，但我想将它们转换为数组以进行映射，我该如何做到这一点？它尚未转换为数组，我尝试了一些互联网上的解决方案，我该如何做到这一点？
Currenlty其给我null，当我首次使用const propertyValues = Object.values(item);时，它给我了ERROR TypeError：undefined is not a function错误
const renderImages = ({ item, index }) => {
console.log(item)
if (!item || !Array.isArray(item)) {
return null;
}
const propertyValues = Object.values(item);
console.log(propertyValues);
return (
<View style={styles.images}>
{item.map((url) => (
<Image key={url} style={styles.pic} source={{ uri: url }} />
))}
</View>
);
};
如果我什么都不做，只是记录item，它会记录类似这样的东西：
LOG {"picture": "https://firebasestorage.googleapis.com/v0/b/myprojectfirebase.appspot.com/o/file%3A%2Fdata%2Fuser%2F0%2Fhost.exp.exponent%2Fcache%2FExperienceData%2F%252540anonymous%25252FYounme-4dc528f7-0647-403c-9671-6a595b71bf0b%2FImagePicker%2Fba5eb500-c4e3-4199-9cef-5a8bfb3b1219.jpeg?alt=media&token=49041038-deef-40d9-9809-41210982ae36"}
{
userdata ?
<FlashList
data={userdata.pictures}
renderItem={renderImages}
keyExtractor={(item, index) => index.toString()}
getItemCount={() => userdata.pictures.length}
getItem={(data, index) => data[index]}
initialNumToRender={5}
windowSize={5}
ListHeaderComponent={
...//
}
}
/>
英文:
ERROR TypeError: undefined is not a function Why my object is not converting to array? this is the error that I am facing I am trying to map all the item which is currently object but I want to convert it to array to map all them how can I do that? its not been converted into array I tried some solutions on internet how can I do that?
Currenlty its giving me null and when i first const propertyValues = Object.values(item); it gave me ERROR TypeError: undefined is not a function error
const renderImages = ({ item, index }) => {
console.log(item)
if (!item || !Array.isArray(item)) {
return null;
}
const propertyValues = Object.values(item);
console.log(propertyValues);
return (
<View style={styles.images}>
{item.map((url) => (
<Image key={url} style={styles.pic} source={{ uri: url }} />
))}
</View>
);
};
If i do nothing just log the item it logs something like this:
LOG {"picture": "https://firebasestorage.googleapis.com/v0/b/myprojectfirebase.appspot.com/o/file%3A%2Fdata%2Fuser%2F0%2Fhost.exp.exponent%2Fcache%2FExperienceData%2F%252540anonymous%25252FYounme-4dc528f7-0647-403c-9671-6a595b71bf0b%2FImagePicker%2Fba5eb500-c4e3-4199-9cef-5a8bfb3b1219.jpeg?alt=media&token=49041038-deef-40d9-9809-41210982ae36"}
{
userdata ?
<FlashList
data={userdata.pictures}
renderItem={renderImages}
keyExtractor={(item, index) => index.toString()}
getItemCount={() => userdata.pictures.length}
getItem={(data, index) => data[index]}
initialNumToRender={5}
windowSize={5}
ListHeaderComponent={
...//
}
}
/>
答案1
得分: 1
如果item是一个对象，此代码将始终返回null：
if (!item || !Array.isArray(item)) {
return null;
}
此外，如果你想创建一个URL数组，你可以简单地使用Object.keys和.map来创建一个item URL 数组。
const properties = Object.keys(item);
const values = properties.map((p) => item[p].url);
由于item只有一个picture，为什么不简化：
const renderImages = ({ item, index }) => {
return (
<View style={styles.images}>
<Image key={item.picture} style={styles.pic} source={{ uri: item.picture }} />
</View>
);
};
英文:
If item is an object, this code will always return null:
if (!item || !Array.isArray(item)) {
return null;
}
Additionally, if you want to create an array of URLs, you can simply use Object.keys and .map to create an array of item urls.
const properties = Object.keys(item);
const values = properties.map((p) => item.url);
Since item just has one picture, why not simplify:
const renderImages = ({ item, index }) => {
return (
<View style={styles.images}>
<Image key={item.picture} style={styles.pic} source={{ uri: item.picture }} />
</View>
);
};
答案2
得分: 1
考虑执行：
const renderImages = ({ item, index }) => {
return (
<View style={styles.images}>
<Image key={url.picture} style={styles.pic} source={{ uri: url.picture }} />
</View>
);
};
英文:
Consider doing:
const renderImages = ({ item, index }) => {
return (
<View style={styles.images}>
<Image key={url.picture} style={styles.pic} source={{ uri: url.picture }} />
</View>
);
};
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