php-求大神解答这个json如何转为数组

求大神解答这个json如何转为数组

 {trend : 3,yearLowPrice : 99.9,points : [['2014-10-29',139.9],['2014-11-11',115.9],['2014-11-12',139.9],['2014-12-12',129],['2014-12-13',139.9],['2015-01-01',119],['2015-01-06',139.9],['2015-02-12',159.9],['2015-02-27',139.9],['2015-03-06',119],['2015-03-08',139.9],['2015-03-23',99.9],['2015-03-27',139.9],['2015-04-27',139.91]]}

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