js对象属性名书写方式

Notation of Keys

[code]var test = {
    'case': 'I am a keyword so I must be notated as a string',
    delete: 'I am a keyword too so me' // raises SyntaxError
};

Object properties can be both notated as plain characters and as strings. Due to another mis-design in JavaScript's parser, the above will throw a

SyntaxError

prior
to ECMAScript 5.

This error arises from the fact that

delete

is a keyword;
therefore, it must be notated as a string
literal to ensure that it will be correctly interpreted by older JavaScript engines.