In JS of LWC, line after forEach statement does not execute

Question

I have below Javascript function in lwc

apexJobInfoData;
@track isBatch;
getData({ error, data }) {
    if (error) {
        // TODO: handle error
    } else if (data) {
        this.jobId = getFieldValue(data, JOB_ID);
        getAllApexJobInfo({ ApexJobId: this.jobId})
        .then(result => {
            this.apexJobInfoData = result.JobInfo.length===0?null:result.JobInfo;
            this.error = undefined;

            if(apexJobInfoData!=null){
                apexJobInfoData.forEach((element) => {
                        if(element.JobType === 'BatchApex'){
                            this.isBatch = true;    
                        }
                  })
            }
            alert('Error Calling Alert Here');  // This line does not execute
        })
        .catch(error => {
            this.message = undefined;
            this.error = error;
        });
    }

I am not sure what's happening but after there is something wrong with below piece of code. After this nothing gets executed.

        if(apexJobInfoData!=null){
            console.log('Enters here');
            apexJobInfoData.forEach((element) => {
                 console.log('Doesn't enter here');
              })
        }

What am I missing here.

Answer 1

Looks to me like you are missing "this" references:

    .then(result => {
        this.apexJobInfoData = result.JobInfo.length===0?null:result.JobInfo;
        this.error = undefined;

        if(this.apexJobInfoData!=null){ // HERE
            this.apexJobInfoData.forEach((element) => { // HERE TOO
                    if(element.JobType === 'BatchApex'){
                        this.isBatch = true;    
                    }
              })
        }