fn main() {
    let arr: [u8;8] = [97, 112, 112, 108, 101];
    println!("Len is {}",arr.len());
    println!("Elements are {:?}",arr);
}

fn main() {
    let arr: [u8;8] = [97, 112, 112, 108, 101];
    println!("Len is {}",arr.len());
    println!("Elements are {:?}",arr);
}

有什么办法可以用0来填充剩余的元素吗？就像是：

let arr: [u8;8] = [97, 112, 112, 108, 101].something();

该脚本无法反序列化我的对象。错误是TypeError: this.buf.readUInt32LE is not a function

TypeError: this.buf.readUInt32LE is not a function
    at BinaryReader.readU32 (index.js:165)
    at BinaryReader.propertyDescriptor.value (index.js:136)
    at BinaryReader.readString (index.js:194)
    at BinaryReader.propertyDescriptor.value (index.js:136)
    at deserializeField (index.js:341)
    at deserializeStruct (index.js:385)
    at Object.deserialize (index.js:403)
    at hello (App.js:52)
    at HTMLUnknownElement.callCallback (react-dom.development.js:3945)
    at Object.invokeGuardedCallbackDev (react-dom.development.js:3994)
    at invokeGuardedCallback (react-dom.development.js:4056)
    at invokeGuardedCallbackAndCatchFirstError (react-dom.development.js:4070)
    at executeDispatch (react-dom.development.js:8243)
    at processDispatchQueueItemsInOrder (react-dom.development.js:8275)
    at processDispatchQueue (react-dom.development.js:8288)
    at dispatchEventsForPlugins (react-dom.development.js:8299)
    at react-dom.development.js:8508
    at batchedEventUpdates$1 (react-dom.development.js:22396)
    at batchedEventUpdates (react-dom.development.js:3745)
    at dispatchEventForPluginEventSystem (react-dom.development.js:8507)
    at attemptToDispatchEvent (react-dom.development.js:6005)
    at dispatchEvent (react-dom.development.js:5924)
    at unstable_runWithPriority …

我的文档数据中有一个 Map 对象。像下面这样

我必须向同一张地图添加新的用户出价，而不删除旧数据，但我使用的代码是用新值替换整个地图。关于如何实现我的目标的任何建议。

FirebaseFirestore.instance.collection('products')
.doc(widget.product.uid).update({
  'bids': {
  auth.currentUser?.email:
      currentPrice.toString()
  }
});

用新向量替换向量特定部分的最佳方法是什么？

截至目前，我正在使用硬编码代码来替换向量。实现这一目标最有效的方法是什么？

fn main() {
    let mut v = vec![1, 2, 3, 4, 5, 6, 7, 8, 9];
    
    let u = vec![0,0,0,0];

    v[2] = u[0];
    v[3] = u[1];
    v[4] = u[2];
    v[5] = u[3];
    

    println!("v = {:?}", v);
}

游乐场的永久链接

是否有任何函数可以用给定的索引替换向量？