我一直在阅读EffectiveJavaItem46:Preferfor-eachloopstotraditionalforloops在提到需要迭代器/for循环而不是for-each循环的情况的部分，有一点:Paralleliteration—Ifyouneedtotraversemultiplecollectionsinparallel,thenyouneedexplicitcontrolovertheiteratororindexvariable,sothatalliteratorsorindexvariablescanbeadvancedinlockstep.现在，我明白了对迭代