#break:终止程序，跳出循环#next:跳到下一个循环,本次循环结果不做处理#redo:在相同的条件下重复刚才的处理i=0names=["Perl","Pyhton","Ruby","Scheme"]names.eachdo|x|i+=1ifi==3breakendp[i,x]endi=0names=["Perl","Pyhton","Ruby","Scheme"]names.eachdo|x|i+=1ifi==3nextendp[i,x]endi=0names=["Perl","Pyhton","Ruby","Scheme"]names.eachdo|x|i+=1ifi==3redoendp[i,x]end