[PHP] 重回基础（Array相关函数），重回array

[PHP] 重回基础（Array相关函数），重回array

使用函数array_keys()，得到数组中所有的键，参数：数组

<span>$arr</span>=<span>array</span><span>();
</span><span>$arr</span>['one']="one"<span>;
</span><span>$arr</span>['two']="two"<span>;
</span><span>$arr</span>['three']="three"<span>;

</span><span>$newArr</span>=<span>array_keys</span>(<span>$arr</span><span>);
</span><span>print_r</span>(<span>$newArr</span><span>);
</span><span>//</span><span>Array ( [0] => one [1] => two [2] => three )</span>

使用函数array_values()，得到数组中所有的值，参数：数组

<span>$arr</span>=<span>array</span><span>();
</span><span>$arr</span>[20]="one"<span>;
</span><span>$arr</span>[30]="two"<span>;
</span><span>$arr</span>[40]="three"<span>;

</span><span>$newArr</span>=<span>array_values</span>(<span>$arr</span><span>);
</span><span>print_r</span>(<span>$newArr</span><span>);
</span><span>//</span><span>Array ( [0] => one [1] => two [2] => three )</span>

使用函数array_map()，使每个元素都调用一下自定义函数，参数：String类型函数名称，数组

<span>$arr</span>=<span>array</span><span>();
</span><span>$arr</span>[0]="one"<span>;
</span><span>$arr</span>[1]="two"<span>;
</span><span>$arr</span>[2]="three"<span>;
</span><span>function</span> test(<span>$v</span><span>){
    </span><span>return</span> <span>$v</span>." Hello"<span>;
}
</span><span>$newArr</span>=<span>array_map</span>("test",<span>$arr</span><span>);
</span><span>print_r</span>(<span>$newArr</span><span>);
</span><span>//</span><span>Array ( [0] => one Hello [1] => two Hello [2] => three Hello )</span>

使用函数array_merge()，把两个数组合并成一个，参数：数组，数组

关联数组合并时，键相同的会被后面的数组覆盖

索引数组合并时，会连接在一起形成一个新的数组

<span>$arr</span>=<span>array</span><span>();
</span><span>$arr</span>[0]="one"<span>;
</span><span>$arr</span>[1]="two"<span>;
</span><span>$arr</span>[2]="three"<span>;

</span><span>$arr1</span>=<span>array</span><span>();
</span><span>$arr</span>[3]="taoshihan1"<span>;
</span><span>$arr</span>[4]="taoshihan2"<span>;
</span><span>$arr</span>[5]="taoshihan3"<span>;

</span><span>$newArr</span>=<span>array_merge</span>(<span>$arr</span>,<span>$arr1</span><span>);
</span><span>print_r</span>(<span>$newArr</span><span>);
</span><span>//</span><span>Array ( [0] => one [1] => two [2] => three [3] => taoshihan1 [4] => taoshihan2 [5] => taoshihan3 )</span>

<span>$arr</span>=<span>array</span>("one","two","three"<span>);
</span><span>$arr1</span>=<span>array</span>("4","5","6"<span>);
</span><span>$newArr</span>=<span>array_merge</span>(<span>$arr</span>,<span>$arr1</span><span>);
</span><span>print_r</span>(<span>$newArr</span><span>);
</span><span>//</span><span>Array ( [0] => one [1] => two [2] => three [3] => 4 [4] => 5 [5] => 6 )</span>

使用函数ksort()，按照键名进行排序，注意没有返回新的数组，还是原来的数组

<span>$arr</span>=<span>array</span>("2"=>"taoshihan2","1"=>"taoshihan1","3"=>"taoshihan3"<span>);
</span><span>ksort</span>(<span>$arr</span><span>);
</span><span>print_r</span>(<span>$arr</span><span>);
</span><span>//</span><span>Array ( [1] => taoshihan1 [2] => taoshihan2 [3] => taoshihan3 )</span>

使用函数array_search()，搜索某个键值，返回对应的键

<span>$arr</span>=<span>array</span>("2"=>"taoshihan2","1"=>"taoshihan1","3"=>"taoshihan3"<span>);
</span><span>echo</span> <span>array_search</span>("taoshihan1",<span>$arr</span><span>);
</span><span>//</span><span> 1</span>