javascript转换 <string, string[]> 至 <string, string>

Question

I have a javascript object with key/value pairs where the value is an array of strings:

var errors = {
    "Message": ["Error #1", "Error #2"],
    "Email": ["Error #3", "Error #4"]
};

I would like to convert this to a key/value pair with the first element of each array so that it is a instead of :

var firstErrorOnly = {
    "Message": "Error #1",
    "Email": "Error #3"
};

I tried doing this using jQuery.map but I was not getting the results I wanted. How can I accomplish this?

Answer 1

You can traverse the whole object using for ... in and hasOwnProperty() to create a new object in the style you wish.

var firstErrorOnly = {};
for( var key in errors ) {
  if ( errors.hasOwnProperty( key ) ) {
    firstErrorOnly[ key ] = errors[key][0];
  }
}

Answer 2

For a jQuery implementation, try this:

var firstErrorOnly = {};
$.each(errors, function(i, value) {
    firstErrorOnly[i] = value[0];
});

Example fiddle