Progressive Web Application Development by Example

Accessing Header values

The get method returns a specific headers value:

Var cacheHeader = myHeaders.get('Cache-Control'); 
    //returns 'private, max-age=3600, s-max-age=300' 

The entries method returns an iterator you can use to loop through all the headers. Each entry is a simple array, with the first entry being the header key name and the second member being the value:

// Display the key/value pairs 
for (var header of myHeaders.entries()) { 
   console.log(header[0]+ ': '+ header[1]); 
} 

The keys method also provides an iterator, but only returns a list of header names:

// Display the keys 
for(var key of myHeaders.keys()) { 
   console.log(key);  
} 

Conversely, you can get a list of values from the values method. The problem with this method is that ...