JS addition, deletion, modification and query of JSON array

Catalog

Query log . according to username Query log

  Delete record . according to username Delete record

  Modify the record . according to username modify password

The new record . 

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Reference resources ：JavaScript（js） In the array Array The common method of _~ Blog in Xinjiang -CSDN Blog _array jsArray.some()var arr=[1, 2, 3, 4, 5]var arr1=arr.some(x => x > 3);console.log(arr) //Array [1, 2, 3, 4, 5]console.log(arr1) //truesome() Method is used to detect whether the elements in the array meet the specified conditions （ Function provides ）.some() Method will execute each element of the array in turn ......https://blog.csdn.net/qq_40323256/article/details/103008280 

Query log . according to username Query log

    const users = [
      { username: " Zhang San ", password: 333 },
      { username: " Li Si ", password: 444 },
      { username: " Wang Wu ", password: 555 },
    ];

    // Query log . according to username Query log 
    let data = users.filter((item) => item.username == " Zhang San ");
    console.log(" according to username Queried records :", data);

  Delete record . according to username Delete record

    const users = [
      { username: " Zhang San ", password: 333 },
      { username: " Li Si ", password: 444 },
      { username: " Wang Wu ", password: 555 },
    ];

    // Delete record . according to username Delete record 
    let data = users.filter((item) => item.username == " Zhang San ");
    console.log(" according to username Queried records :", data);
    let index = users.indexOf(data[0]);
    console.log(" Indexes index:", index);
    index !== -1 && users.splice(index, 1);
    console.log(" After deleting a record users:", users);

  Modify the record . according to username modify password

    const users = [
      { username: " Zhang San ", password: 333 },
      { username: " Li Si ", password: 444 },
      { username: " Wang Wu ", password: 555 },
    ];

    // Modify the record . according to username modify password
    let data = users.filter((item) => item.username == " Zhang San ");
    console.log(" according to username Queried records :", data);
    data[0].password = 3333;
    console.log(" After modifying a record users:", users);

The new record . 

 

    const users = [
      { username: " Zhang San ", password: 333 },
      { username: " Li Si ", password: 444 },
      { username: " Wang Wu ", password: 555 },
    ];

    // The new record .
    users.push({ username: " Zhao Liu ", password: 666 });
    console.log(" After adding a new record users:", users);