📜  javascript for 对象上的循环 - Javascript 代码示例

📅  最后修改于: 2022-03-11 15:01:09.946000             🧑  作者: Mango

代码示例6
/Example 1: Loop Through Object Using for...in
// program to loop through an object using for...in loop

const student = { 
    name: 'John',
    age: 20,
    hobbies: ['reading', 'games', 'coding'],
};

// using for...in
for (let key in student) { 
    let value;

    // get the value
    value = student[key];

    console.log(key + " - " +  value); 
} 

/Output
    name - John
    age - 20
    hobbies - ["reading", "games", "coding"]

//If you want, you can only loop through the object's
//own property by using the hasOwnProperty() method.

if (student.hasOwnProperty(key)) {
    ++count:
}

/////////////////////////////////////////

/Example 2: Loop Through Object Using Object.entries and for...of
// program to loop through an object using for...in loop

const student = { 
    name: 'John',
    age: 20,
    hobbies: ['reading', 'games', 'coding'],
};

// using Object.entries
// using for...of loop
for (let [key, value] of Object.entries(student)) {
    console.log(key + " - " +  value);
}
/Output
    name - John
    age - 20
    hobbies - ["reading", "games", "coding"]

//In the above program, the object is looped using the
//Object.entries() method and the for...of loop.

//The Object.entries() method returns an array of a given object's key/value pairs.
//The for...of loop is used to loop through an array.

//////////////////////////////////////////////////////////