How To Read First Character Of String Inside An Array Without Using String.charAt()?

Suppose I have an array with strings: ['1234', '1223', '5454', 'abc', 'abdd'] And I want to read the first character of each string and put it into an new array: ['1', '1', '5', '

Solution 1:

You need to use map instead of filter.

var strings = ["1234", "1223", "5454", "abc", "abdd"]

var firstChars = strings.map(function (string) {
    return string[0];
})

console.log(firstChars)

Solution 2:

With ES6, you could use a destructuring assignment, because strings are iterables.

var array = ["1234", "1223", "5454", "abc", "abdd"];
    result = array.map(([a]) => a);
    
console.log(result);

Solution 3:

You can use.

var testArr = ["1234", "1223", "5454", "abc", "abdd"],
newArr = [];

testArr.forEach( function(str){
    newArr.push(str.substring(0,1));
});

Better functional and efficient version.

var testArr = ["1234", "1223", "5454", "abc", "abdd"];


function getFirst(arr){
   return arr.map(function(str){
       return str.substring(0,1);
   });
}

console.log(getFirst(testArr));

Best videos for understanding the array methods The Array ForEach Method