array

• How arrays are defined
• Format 1: array(value 1, value 2, value 3);
• Array without specifying a subscript, the subscript is a continuously increasing value
• Format 2: array(key=>value, key=>value);
• Specify the subscript, the subscript is the value specified by the user (string, value)
• Declare the array using the specified syntax php version > 5.3
• Format 1: array variable = [value1, value2];
• Do not specify a subscript, declare an indexed array
• Format 2: array variable=[key=>value, key=>value];
• Specify the subscript, the subscript is the value specified by the user
• Declare an array by adding array elements directly
• Format 1: array variable[]=value
• The subscript of the array declared in this way is a continuous index array starting from 0
• Format 2: array variable [subscript] = value;
• Declare arrays by adding elements, either associative arrays or indexed arrays