Note: To extract characters from the end of the string, use a negative start number.

注意：要从字符的尾部开始取字符，用负数做为起始字符。

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For example, you can convert the string "1234" to a number.

例如，您可以将“1234”字串转换为一个数字。

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And it boils down to modifying the format string with just a simple number.

它归结于是用一个简单的数字来，修改字符串的格式。

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Some types of conversions, such as from a string to a number, are time-consuming.

有些转换类型十分耗费时间，例如从字串转换为数字。

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Note: To extract characters from the end of the string, use a negative start number.

注意：要从字符的末尾开始选取字符，用一个负的起始值。

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Note: To extract characters from the end of the string, use a negative start number.

注意：要从字符的末尾开始选取字符，用一个负的起始值。

youdao