javascript increment from number to string

Question

How can I parse number to string for increment? Do I have to make 2 line statement? Below code is not valid.

['a', 'b'].map((o,i)=>({myStr: ++i.toString()}))

ignore the array, it's just sample, I expect this [{myStr: "1"},{myStr:"2"}] where i is the index of map.

The input array doesn't contain numbers? What exactly would your expected output be? And why? — LukStorms
– LukStorms, Commented Jul 7, 2018 at 14:45

Marcos Casagrande · Accepted Answer · 2018-07-07 14:49:10Z

2

You have to wrap ++i: (++i).toString();

const res = ['a', 'b'].map((o,i) => ({myStr: (++i).toString()} ));
console.log(res);

You can also use template literals:

 const res = ['a', 'b'].map((o,i) => ({myStr: `${++i}`} ));
 console.log(res);

answered Jul 7, 2018 at 14:49

Marcos Casagrande

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Comments

Leonid Pyrlia · Accepted Answer · 2018-07-07 14:53:54Z

1

Wrap ++i in a String constructor:

['a', 'b'].map((o,i)=>({myStr: String(++i)}))

answered Jul 7, 2018 at 14:53

Leonid Pyrlia

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vadim savin · Accepted Answer · 2018-07-07 14:50:44Z

0

 var arr = ['a', 'b'];
 var newArr = arr.map((o,i)=>({myStr: (++i).toString()}))

answered Jul 7, 2018 at 14:50

vadim savin

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