N/record Module
Record.setSublistValue()
Method Description: Sets the value of a sublist field. (standard mode only — see SuiteScript 2.0 – Standard and Dynamic Modes) When working in dynamic mode, set a sublist field value using the following methods: Record.selectLine(options) Record.setCurrentSublistValue(options) Record.commitLine(options) When you edit a sublist line with SuiteScript, it triggers an internal validation of the sublist line. If the line validation fails, the script also fails. For example, if your script edits a closed catch up period, the validation fails and prevents SuiteScript from editing the closed catch up period. Sets a numeric value for rate and ratehighprecision fields.
Returns: record.Record
Supported Script Types: Client and server-side scripts For more information, see SuiteScript 2.0 Script Types.
Governance: None
Module: N/record Module
Sibling Object Members: Record Object Members
Since: 2015.2
Search NetSuite - https://system.netsuite.com/app/help/helpcenter.nl?search=Record.setSublistValue(options)

// Code Example 1

// Add additional code.

//...

objRecord.setSublistValue({

    sublistId: 'item',

    fieldId: 'item',

    line: 3,

    value: true

});

//...

// Add additional code.



//SOURCE: https://system.netsuite.com/app/help/helpcenter.nl?fid=section_4273166777.html