I want splice the line with value = 3

[3,"John", 90909090]

data.json

{
"headers":[[
{"text":"Code","class":"Code"},
{"text":"Code","class":"Code"}
]],
"rows":[
[0,"Peter", 51123123],
[3,"John", 90909090],
[5,"Mary",51123123]
],
"config":[[0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]],
"other":[[13,0]]
}

I try this:

var size = data.rows.length; // number of rows

var del = 3 // Value of ID to be deleted          

for (i = 0; i < size; i++) {  

var id = data.rows[i][0];                  

    if(del==id){  // if del = id -> splice                                         

       data.rows.splice(i,1);

    }

}

Results:

Only splice or only loop this code works.

But, with both show this error:

Uncaught TypeError: Cannot read property '0' of undefined(…)

It occurs in "data.rows[i][0]"

I want splice the line with value = 3

[3,"John", 90909090]

data.json

{
"headers":[[
{"text":"Code","class":"Code"},
{"text":"Code","class":"Code"}
]],
"rows":[
[0,"Peter", 51123123],
[3,"John", 90909090],
[5,"Mary",51123123]
],
"config":[[0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]],
"other":[[13,0]]
}

I try this:

var size = data.rows.length; // number of rows

var del = 3 // Value of ID to be deleted          

for (i = 0; i < size; i++) {  

var id = data.rows[i][0];                  

    if(del==id){  // if del = id -> splice                                         

       data.rows.splice(i,1);

    }

}

Results:

Only splice or only loop this code works.

But, with both show this error:

Uncaught TypeError: Cannot read property '0' of undefined(…)

It occurs in "data.rows[i][0]"

• javascript
• jquery

Share Improve this question Follow asked Nov 16, 2016 at 12:03 GurigraphicsGurigraphics 33133 silver badges1212 bronze badges 2

• 1 This is a good example of premature micro-optimization wasting your time. There isn't any need to use that size variable; just pare with data.rows.length directly. If you had, you wouldn't have run into this error. (You also would have kept processing further entries. Whether you want to do that depends on whether 3 could appear more than once in the array...) – T.J. Crowder Commented Nov 16, 2016 at 12:06
• Truth. \o/ Thank you. – Gurigraphics Commented Nov 16, 2016 at 12:15

Add a ment  | 

4 Answers 4

Sorted by: Reset to default 3

instead of using a for loop, id use the array filter function:

data.rows = data.rows.filter(function(row){
    return row[0] !== del;
});

Just add a break to the condition, because the next element, is the one you have spliced, which is not anymore in the array.

if (del == id) {  // if del = id -> splice
   data.rows.splice(i, 1);
   break; // no more to search
}

You can iterate with Array#forEach():

var data = {"headers": [[{"text": "Code","class": "Code"}, {"text": "Code","class": "Code"}]],"rows": [[0, "Peter", 51123123],[3, "John", 90909090],[5, "Mary", 51123123]],"config": [[0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]],"other": [[13, 0]]},
    del = 3; // Value of ID to be deleted

data.rows.forEach(function(item, index) {
  item[0] === del && data.rows.splice(index, 1);
});

console.log(data.rows);

.as-console-wrapper { max-height: 100% !important; top: 0; }

ES6:

data.rows.forEach((item, index) => item[0] === del && data.rows.splice(index, 1));

You can use lodash for filter your objects or arrays. Look at the filter method for your case:

var myObject = {
"headers":[[
{"text":"Code","class":"Code"},
{"text":"Code","class":"Code"}
]],
"rows":[
[0,"Peter", 51123123],
[3,"John", 90909090],
[5,"Mary",51123123]
],
"config":[[0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]],
"other":[[13,0]]
};

//filter by lodash
myObject.rows =  _.filter(myObject.rows,function(row){
  return row[0] !== 3;
});