CODEWITHSUNDEEP
javascriptarrays
user2319726
user2319726

Reputation: 143

Delete data from object

I have below object and need to delete the column from the result, I will get the column name dynamically. Could you please help me how to delete the column and its corresponding object based on column name {"columnname":"couln2", "datatype":null} Array is:

{
"tabl1":
{"tablename":"tabl1","tablecolumns":"yes","patternCheckStatus":true,
"columns": [{"columnname":"column1","datatype":"Numeric","patternregex":"jjj"},{"columnname":"column2","datatype":"UpperCase","patternregex":"hkl;;"}]},
"table2":{"tablename":"table2","tablecolumns":"yes","patternCheckStatus":null,
"columns":[{"columnname":"t2column","datatype":"Alphabetic"}]
}}


let arr = 
    {"tabl1":{"tablename":"tabl1","tablecolumns":"yes","patternCheckStatus":true,"columns":[{"columnname":"column1","datatype":"Numeric","patternregex":"jjj"},{"columnname":"column2","datatype":"UpperCase","patternregex":"hkl;;"}]},"table2":{"tablename":"table2","tablecolumns":"yes","patternCheckStatus":null,"columns":[{"columnname":"t2column","datatype":"Alphabetic"}]}}


   

    const result = arr.reduce((a, {tablename, tablecolumns, columnname, datatype})   => {
        a[tablename] = a[tablename] || {tablename, tablecolumns, columns: []};
        if (columnname)
          a[tablename].columns.push({columnname, datatype});
        return a;
      },{})
    console.log(Object.values(result));

Upvotes: 1

Views: 474

Answers (3)

StepUp
StepUp

Reputation: 38094

If you want to get rid of some columns in array, then you can use Object.entries while map your array into another array:

let propertyName = 'tablename';
arr.map(s=> Object.fromEntries(Object.entries(s).filter(([k, v]) => k!= propertyName)))

An example:

let arr = [
    {"tablename":"table1","tablecolumns":"yes"},
    {"tablename":"table1","columnname":"col1","datatype":"Alphabetic"},
    {"tablename":"table2","tablecolumns":"yes"},
    {"tablename":"table2","columnname":"tabl2_colu","datatype":null},
    {"tablename":"table2","columnname":"tab2_col2","datatype":"Numeric"}
];

const result = arr.reduce((a, {tablename, tablecolumns, columnname, datatype})   => {
    a[tablename] = a[tablename] || {tablename, tablecolumns, columns: []};
    if (columnname)
        a[tablename].columns.push({columnname, datatype});
    return a;
    },{})

let propertyName = 'tablename';
console.log(Object.values(result)
    .map(s=> Object.fromEntries(Object.entries(s)
        .filter(([k, v]) => k!= propertyName))));

UPDATE:

You can filter your array based in columnname:

let columnname = 'column2';
obj.tabl1.columns = obj.tabl1.columns.filter(f=> f.columnname != columnname);

An example:

let obj = { "tabl1":
  { "tablename": "tabl1", "tablecolumns": "yes", "patternCheckStatus": true,
  "columns": [{ "columnname": "column1", "datatype": "Numeric", "patternregex": "jjj" },
  { "columnname": "column2", "datatype": "UpperCase", "patternregex": "hkl;;" }] }, };

let columnname = 'column2';
obj.tabl1.columns = obj.tabl1.columns.filter(f=> f.columnname != columnname);
console.log(obj);

Upvotes: 0

Jazzpaths
Jazzpaths

Reputation: 709

One way would be to loop through the array of objects, find the one you want to delete by the mean of its property identifier and them just remove that object from the array:

arr = [
{"tablename":"table1","tablecolumns":"yes"},
{"tablename":"table1","columnname":"col1","datatype":"Alphabetic"},
{"tablename":"table2","tablecolumns":"yes"},
{"tablename":"table2","columnname":"tabl2_colu","datatype":null},
{"tablename":"table2","columnname":"tab2_col2","datatype":"Numeric"}
];

function remove_object_by_colname( colname )
  arr.forEach(function( arrayItem, index ) {
    if ( arrayItem.columnname == colname ) {
      arr.splice( index, 1 );
    }
  };
} );

remove_object_by_colname( 'tabl2_colu' ); // Will remove the 4th object from arr.

Upvotes: 0

Nipun Jain
Nipun Jain

Reputation: 1014

I cannot understand your question correctly but I think you want to delete a specific object having a specific columnname value from the arr. You can filter the arr like this:

function deleteColumn (column) {
  let newArr = arr.filter(item => {
     return item.columnname !== column
  })
  return newArr
}

Then you can run:

deleteColumn('tabl2_colu') // Will return an array without object having any columnname = 'tabl2_colu'

Upvotes: 1

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