将php数组转换为更新的方括号版本

I'm new to PHP. I'm trying use the new(ish) format square brackets for an array assigned to variables.

This is it in the old format:

$header = array('Accept: application/json','Content-Type: application/json','Authorization: Bearer ACCESSTOKEN','x-api-key: APIKEY','x-proxy-global-company-id: COMPANYID');

This is what the tutorial talks about for the style of new brakets:

$array = [
    "foo" => "bar",
    "bar" => "foo",
];
?>

The items I want is like the following in my header:

Accept: application/json
Content-Type: application/json
Authorization: Bearer ACCESSTOKEN
x-api-key: APIKEY
x-proxy-global-company-id: COMPANYID

Therefore I thought my header variable should be assigned an array like this:

$header = [
"Accept: application/json",
"Content-Type: application/json",
"Authorization: Bearer ACCESSTOKEN",
"x-api-key: APIKEY",
"x-proxy-global-company-id: COMPANYID",
];

This doesn't validate so I know I'm wrong. It says unexpected T string on line 5. Can anyone give me a tip on where I have gone wrong please?

Your header should be like below:

$header = [
    "Accept" => "application/json",
    "Content-Type" => "application/json",
    "Authorization" => "Bearer ACCESSTOKEN",
    "x-api-key" => "APIKEY",
    "x-proxy-global-company-id" => "COMPANYID",
];