ee.List.get
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Cách sử dụng | Giá trị trả về |
---|
List.get(index) | Đối tượng |
Đối số | Loại | Thông tin chi tiết |
---|
this: list | Danh sách | |
index | Số nguyên | |
Ví dụ
Trình soạn thảo mã (JavaScript)
// An ee.List object.
var list = ee.List([5, 10, 15, 20, 25, 30]);
// Fetch elements at specified 0-based positions in the list.
print('The second element', list.get(1));
print('The fourth element', list.get(3));
print('The last element', list.get(-1));
print('The second to last element', list.get(-2));
// ee.Number and integer computed objects are valid inputs.
print('Computed object index input', list.get(list.get(0)));
// The result of ee.List.get is an ambiguous object type. You need to cast the
// result to the expected type to use it in subsequent instance methods. For
// example, if you are fetching a number and wish to add it to another number,
// you must cast the .get() result as an ee.Number.
print('Add fetched number to another number', ee.Number(list.get(1)).add(2));
Thiết lập Python
Hãy xem trang
Môi trường Python để biết thông tin về API Python và cách sử dụng geemap
cho quá trình phát triển tương tác.
import ee
import geemap.core as geemap
Colab (Python)
# An ee.List object.
ee_list = ee.List([5, 10, 15, 20, 25, 30])
# Fetch elements at specified 0-based positions in the list.
print('The second element:', ee_list.get(1).getInfo())
print('The fourth element:', ee_list.get(3).getInfo())
print('The last element:', ee_list.get(-1).getInfo())
print('The second to last element:', ee_list.get(-2).getInfo())
# ee.Number and integer computed objects are valid inputs.
print('Computed object index input:', ee_list.get(list.get(0)).getInfo())
# The result of ee.List.get is an ambiguous object type. You need to cast the
# result to the expected type to use it in subsequent instance methods. For
# example, if you are fetching a number and wish to add it to another number,
# you must cast the .get() result as an ee.Number.
print('Add fetched number to another number:',
ee.Number(list.get(1)).add(2).getInfo())
Trừ phi có lưu ý khác, nội dung của trang này được cấp phép theo Giấy phép ghi nhận tác giả 4.0 của Creative Commons và các mẫu mã lập trình được cấp phép theo Giấy phép Apache 2.0. Để biết thông tin chi tiết, vui lòng tham khảo Chính sách trang web của Google Developers. Java là nhãn hiệu đã đăng ký của Oracle và/hoặc các đơn vị liên kết với Oracle.
Cập nhật lần gần đây nhất: 2025-07-26 UTC.
[null,null,["Cập nhật lần gần đây nhất: 2025-07-26 UTC."],[[["\u003cp\u003e\u003ccode\u003eList.get()\u003c/code\u003e retrieves an element from an Earth Engine List object at a specified index.\u003c/p\u003e\n"],["\u003cp\u003eNegative index values can be used to access elements from the end of the list, with -1 representing the last element.\u003c/p\u003e\n"],["\u003cp\u003eThe returned element's type is ambiguous and might require explicit casting to a specific Earth Engine type for further operations (e.g., converting to ee.Number to perform calculations).\u003c/p\u003e\n"],["\u003cp\u003eInput indices can be integers, ee.Number objects, or other computed objects that evaluate to an integer.\u003c/p\u003e\n"]]],[],null,["# ee.List.get\n\nReturns the element at the specified position in list. A negative index counts backwards from the end of the list.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|-------------------|---------|\n| List.get`(index)` | Object |\n\n| Argument | Type | Details |\n|--------------|---------|---------|\n| this: `list` | List | |\n| `index` | Integer | |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// An ee.List object.\nvar list = ee.List([5, 10, 15, 20, 25, 30]);\n\n// Fetch elements at specified 0-based positions in the list.\nprint('The second element', list.get(1));\nprint('The fourth element', list.get(3));\nprint('The last element', list.get(-1));\nprint('The second to last element', list.get(-2));\n\n// ee.Number and integer computed objects are valid inputs.\nprint('Computed object index input', list.get(list.get(0)));\n\n// The result of ee.List.get is an ambiguous object type. You need to cast the\n// result to the expected type to use it in subsequent instance methods. For\n// example, if you are fetching a number and wish to add it to another number,\n// you must cast the .get() result as an ee.Number.\nprint('Add fetched number to another number', ee.Number(list.get(1)).add(2));\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# An ee.List object.\nee_list = ee.List([5, 10, 15, 20, 25, 30])\n\n# Fetch elements at specified 0-based positions in the list.\nprint('The second element:', ee_list.get(1).getInfo())\nprint('The fourth element:', ee_list.get(3).getInfo())\nprint('The last element:', ee_list.get(-1).getInfo())\nprint('The second to last element:', ee_list.get(-2).getInfo())\n\n# ee.Number and integer computed objects are valid inputs.\nprint('Computed object index input:', ee_list.get(list.get(0)).getInfo())\n\n# The result of ee.List.get is an ambiguous object type. You need to cast the\n# result to the expected type to use it in subsequent instance methods. For\n# example, if you are fetching a number and wish to add it to another number,\n# you must cast the .get() result as an ee.Number.\nprint('Add fetched number to another number:',\n ee.Number(list.get(1)).add(2).getInfo())\n```"]]