jquery - Uncaught TypeError: Cannot read property 'indexOf' of undefined in javascript - Stack Overflow

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var id    = $('.getval_'+product_id+''+index+'').attr("id");
var value = "";

console.log(id);
//data that return by id
6059
s2id_6061
6122
s2id_8410

if (id.indexOf('s2id_') > 0) {
    value = $('.getval_'+product_id+''+index+'').select2('val');
}else{      
    value = $('.getval_'+product_id+''+index+'').val();
}

Question: The code above is show that when the ID return by jquery, then it will show a list of data, so what I want is when the ID return, if the in front of ID don't have s2id_ it will go else statement. But the code return an error which is (Uncaught TypeError: Cannot read property 'indexOf' of undefined)

var id    = $('.getval_'+product_id+''+index+'').attr("id");
var value = "";

console.log(id);
//data that return by id
6059
s2id_6061
6122
s2id_8410

if (id.indexOf('s2id_') > 0) {
    value = $('.getval_'+product_id+''+index+'').select2('val');
}else{      
    value = $('.getval_'+product_id+''+index+'').val();
}

Question: The code above is show that when the ID return by jquery, then it will show a list of data, so what I want is when the ID return, if the in front of ID don't have s2id_ it will go else statement. But the code return an error which is (Uncaught TypeError: Cannot read property 'indexOf' of undefined)

• javascript
• jquery

Share Follow edited Jun 9, 2017 at 4:51 ASR 1,81155 gold badges2525 silver badges3333 bronze badges asked Jun 9, 2017 at 3:01 Ch HongCh Hong 37811 gold badge66 silver badges2020 bronze badges 1

• 1 +''? This is not needed at any point in your code. – nnnnnn Commented Jun 9, 2017 at 3:04

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1 Answer 1

Sorted by: Reset to default 4

You need to check whether id itself is set, and there are two ways of going about this.

Either chain the if (id.indexOf('s2id_') > 0) condition inside an outer if condition that checks for id:

if (id) {
    if (id.indexOf('s2id_') > 0) {
        value = $('.getval_'+product_id+''+index+'').select2('val');
    }else{      
        value = $('.getval_'+product_id+''+index+'').val();
    }
}

Or check for both conditions with an and statement:

if (id && id.indexOf('s2id_') > 0) {
    value = $('.getval_'+product_id+''+index+'').select2('val');
}else{      
    value = $('.getval_'+product_id+''+index+'').val();
}

Hope this helps! :)

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