How does jquery set the first or last radio of a single worker as the selected value?

Inputradio Singleton is often used in project development. Sometimes we need to use js to control the selected value of Singleton radio, this article explains how to set the first or last radio of a single worker as the selected value in jquery. For more information about the coders, see. The html code used in this example:

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Set the first Radio as the selected value:

$ ('Input: radio: first '). attr ('checked', 'checked'); or $ ('input: radio: first '). attr ('checked', 'true ');

Set the last Radio as the selected value:

$ ('Input: radio: lae '). attr ('checked', 'checked'); or $ ('input: radio: lae '). attr ('checked', 'true ');

Note:Attr ("checked", 'checked') = attr ("checked", 'true') = attr ("checked", true)