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2025 年 4 月 15 日前註冊使用 Earth Engine 的非商業專案，都必須
驗證非商業用途資格，才能繼續存取 Earth Engine。
ee.Number.evaluate
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
從伺服器非同步擷取這個物件的值，並傳遞至提供的回呼函式。
| 用量 | 傳回 |
|---|
Number.evaluate(callback) | |
| 引數 | 類型 | 詳細資料 |
|---|
這個：computedobject | ComputedObject | ComputedObject 例項。 |
callback | 函式 | 伺服器傳回答案時呼叫的函式，格式為 function(success, failure)。如果要求成功，success 引數會包含評估結果。如果要求失敗，失敗引數會包含錯誤訊息。 |
範例
程式碼編輯器 (JavaScript)
/**
* WARNING: this function transfers data from Earth Engine servers to the
* client. Doing so can negatively affect request processing and client
* performance. Server-side options should be used whenever possible.
* Learn more about the distinction between server and client:
* https://developers.google.com/earth-engine/guides/client_server
*/
// A server-side ee.Number object.
var numberServer = ee.Number(10.3);
// Use evaluate to transfer server-side number to the client.
numberServer.evaluate(function(numberClient) {
print('Client-side primitive data type', typeof numberClient); // number
print('Client-side number', numberClient); // 10.3
print('Client-side number used in expression', numberClient + 10); // 20.3
});
Python 設定
請參閱
Python 環境頁面，瞭解 Python API 和如何使用 geemap 進行互動式開發。
import ee
import geemap.core as geemap
Colab (Python)
# The Earth Engine Python client library does not have an evaluate method for
# asynchronous evaluation of ee.Number objects.
# Use ee.Number.getInfo() instead.
除非另有註明，否則本頁面中的內容是採用創用 CC 姓名標示 4.0 授權，程式碼範例則為阿帕契 2.0 授權。詳情請參閱《Google Developers 網站政策》。Java 是 Oracle 和/或其關聯企業的註冊商標。
上次更新時間：2025-07-26 (世界標準時間)。
[null,null,["上次更新時間：2025-07-26 (世界標準時間)。"],[[["\u003cp\u003e\u003ccode\u003eevaluate()\u003c/code\u003e is a method of the \u003ccode\u003eComputedObject\u003c/code\u003e class and allows retrieving the value of the object from the Earth Engine server asynchronously.\u003c/p\u003e\n"],["\u003cp\u003eIt takes a callback function that handles the evaluated result or any potential errors encountered during evaluation.\u003c/p\u003e\n"],["\u003cp\u003eThe provided example demonstrates how to use \u003ccode\u003eevaluate()\u003c/code\u003e to transfer a server-side \u003ccode\u003eee.Number\u003c/code\u003e to the client in JavaScript.\u003c/p\u003e\n"],["\u003cp\u003eWhile JavaScript utilizes \u003ccode\u003eevaluate()\u003c/code\u003e, the Python client library recommends using \u003ccode\u003egetInfo()\u003c/code\u003e for similar asynchronous evaluation of \u003ccode\u003eee.Number\u003c/code\u003e objects.\u003c/p\u003e\n"]]],["The `evaluate` method asynchronously retrieves a `ComputedObject`'s value from the server and provides it to a callback function. The callback receives a success argument with the result or a failure argument with an error message. It's called on a `Number` object. The examples demonstrated transfering a server-side number to the client, using the retrieved value. Python does not have this method and recommends `getInfo()` instead.\n"],null,["# ee.Number.evaluate\n\n\u003cbr /\u003e\n\nAsynchronously retrieves the value of this object from the server and passes it to the provided callback function.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|-----------------------------|---------|\n| Number.evaluate`(callback)` | |\n\n| Argument | Type | Details |\n|------------------------|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| this: `computedobject` | ComputedObject | The ComputedObject instance. |\n| `callback` | Function | A function of the form function(success, failure), called when the server returns an answer. If the request succeeded, the success argument contains the evaluated result. If the request failed, the failure argument will contains an error message. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n/**\n * WARNING: this function transfers data from Earth Engine servers to the\n * client. Doing so can negatively affect request processing and client\n * performance. Server-side options should be used whenever possible.\n * Learn more about the distinction between server and client:\n * https://developers.google.com/earth-engine/guides/client_server\n */\n\n// A server-side ee.Number object.\nvar numberServer = ee.Number(10.3);\n\n// Use evaluate to transfer server-side number to the client.\nnumberServer.evaluate(function(numberClient) {\n print('Client-side primitive data type', typeof numberClient); // number\n print('Client-side number', numberClient); // 10.3\n print('Client-side number used in expression', numberClient + 10); // 20.3\n});\n```\nPython setup\n\nSee the [Python Environment](/earth-engine/guides/python_install) page for information on the Python API and using\n`geemap` for interactive development. \n\n```python\nimport ee\nimport geemap.core as geemap\n```\n\n### Colab (Python)\n\n```python\n# The Earth Engine Python client library does not have an evaluate method for\n# asynchronous evaluation of ee.Number objects.\n# Use ee.Number.getInfo() instead.\n```"]]
