1. 增值：NextIcon()方法从模式中提取当前索引值,并以增值(increment)顺序取下一个索引,假如当前索引位于列表的最后,则运用nextIcon()会返回到第一个值. PrevIcon()方法的功能正好相反,它以递减(decrement)的顺序取列表中的前一个值,

2. 递增：语句'$a++'没有任何值(不是一个),并且因此你不能给它赋值或以任何方式来使用它.PHP通过发展这些加强了递增(increment)/递减(decrement)的能力,

1. 增加量;增长额
    An increment in something or in the value of something is an amount by which it increases.

increment

    e.g. The average yearly increment in labour productivity in industry was 4.5 per cent...
           工业劳动生产率年平均增长 4.5%。
    e.g. Each increment of knowledge tells us more of our world.
           知识的点滴增长都会增进我们对世界的认知。

2. (某一固定时期后自动的)加薪
    An increment is an amount by which your salary automatically increases after a fixed period of time.

    e.g. Many teachers qualify for an annual increment.
           许多老师都有资格获得每年的加薪。

1. the amount by which something increases

    e.g. they proposed an increase of 15 percent in the fare

    Synonym: increase

2. a process of becoming larger or longer or more numerous or more important

    e.g. the increase in unemployment
           the growth of population

    Synonym: increasegrowth