Object properties
Description
Object properties are data value grouped into object.
Example
The following code shows how to access properties via bracket notation.
var tutorial = {
name : "JavaScript",
pageSize : 9 /* w w w .j a va2 s . c o m*/
};
console.log(tutorial["name"]); //"JavaScript"
console.log(tutorial.name); //"JavaScript"
The code above generates the following result.
Example 2
The following code uses variables for property access.
var tutorial = {
name : "JavaScript",
pageSize : 9 /*from w ww. j a v a2s . c o m*/
};
var propertyName = "name";
console.log(tutorial[propertyName]); //"JavaScript"
The code above generates the following result.
Example 3
The following code uses bracket notation when the property name contains space:
var tutorial = {
"tutorial name" : "JavaScript",
pageSize : 9 //from ww w.ja v a 2s . c o m
};
console.log(tutorial["tutorial name"]);
The code above generates the following result.
Example 4
The for...in loop performs the statement for each property.
var myData = {
name : "JavaScript",
weather : "Good",
printMessages : function() {/*from w w w. java 2 s . c om*/
console.log("Hello " + this.name + ". ");
console.log(this.name +" is " + this.weather + ".");
}
};
myData.printMessages();
for ( var prop in myData) {
console.log("Name: " + prop + " Value: " + myData[prop]);
}
The code above generates the following result.
Example 5
A comma separates properties in an object literal. There is no need to add comma for the last property.
Property names can also be specified as strings or numbers:
var tutorial= {
"name" : "JavaScript",
"pageSize" : 9,
1: true //from w ww .j a va2 s. com
};
console.log(tutorial.name); //JavaScript
console.log(tutorial.pageSize); //9
console.log(tutorial["1"]); //
The code above generates the following result.
Example 6
Object literals can also be used to pass a large number of optional arguments to a function:
function displayInfo(args) { /* ww w. j a va 2s . co m*/
if (typeof args.name == "string"){
console.log("Name: " + args.name);
}
if (typeof args.pageSize == "number") {
console.log("PageSize: " + args.age);
}
}
displayInfo({
name: "JavaScript",
pageSize: 9
});
displayInfo({
name: "HTML"
});
The code above generates the following result.
