var str="this is a javascript book!"; index=str.lastIndexOf("i",3); alert(index); 为什么输出2啊?var str="this is a javascript book!";index=str.lastIndexOf("i",5);alert(index);str.lastIndexof("字符",数字),数字是从哪开始数?怎么数?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/05 14:53:58
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