Arrays are composed of multiple arrays based on the same Val value

The original array is similar

$arr        =   Array (            ' id ' = ' 1 '  ,                ' name ' = '  a ',                ' project '   =  ' 1 ',            ),            array (                ' id '    = '  2 ',                ' name '      = '  B ',                ' Project '   =  ' 3 ',            ),            array (                ' id '    = '  3 ',                ' name '      = ' =  ') C ',                ' project '   =  ' 2 ',            ),            array (                ' id '  = ' 4 ',                ' name '      = >  ' d ',                ' project '   =  ' 1 ',            ),        );

I want to make multiple arrays based on the same nature of project, such as the following results

$arr 1        =   Array (            ' id ' = '  1 ',                ' name ' = '  a ',                ' project '   =  ' 1 ',            ),            array (                ' id '    = '  4 ',                ' name '      = '  d ',                ' project '   =  ' 1 ',            )        ;        $arr 2        =   Array (            ' id ' = '  2 ',                ' name ' = '      B '  ,                ' Project '   =  ' 3 ',            ),        );        $arr 3        =   Array (            ' id ' = '  3 ',                ' name ' = '      C '  ,                ' Project '   =  ' 2 ',            ),        );

Ask for help, I have a train of thought, want to let project order, and then loop to determine whether the next Val[project] is the same as the previous, the new array is formed.
But there are other ways to do it.

Reply to discussion (solution)

$arr        =   Array (            ' id ' = ' 1 '  ,                ' name ' = '  a ',                ' project '   =  ' 1 ',            ),            array (                ' id '    = '  2 ',                ' name '      = '  B ',                ' Project '   =  ' 3 ',            ),            array (                ' id '    = '  3 ',                ' name '      = ' =  ') C ',                ' project '   =  ' 2 ',            ),            array (                ' id '  = ' 4 ',                ' name '      = >  ' d ',                ' project '   =  ' 1 ',            )        ; foreach ($arr as $v) $r [' arr '. $v [' project ']][] = $ V;extract ($r);p Rint_r ($arr 1);

Array (    [0] = = Array        (            [id] = 1            [name] + a            [Project] = 1        )    [1] = = Array        (            [id] = 4            [name] + D            [Project] = 1        ))

Other self-authentication

Extract () When do you usually use

Thank you, for the first time know $r[' arr '. $v [' project ']][] = $v; You can also let the array to find the corresponding location, in fact, this sentence to reach the results I want, I kind of way I feel tired

Extract () looked at it before, roughly giving Val directly to the variable in the $+key name.

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