JS: Iterate String

Loop thru characters in string

Best way to go thru each char in string is using for-of Loop.

for (let x of "a🦋c") console.log(x);
/*
a
🦋
c
*/

Convert string to array

you can convert string to array, using Array.from.

• JS: Array.from

console.log(
 Array.from("a🦋c"),
);
// [ "a", "🦋", "c" ]

Array.from also lets you apply a function to the array.

// using Array.from to map a function over characters in string

console.log(
 Array.from(
  "a🦋c",
  (x, i) => `char at index ${i} is ${x}`,
 ),
);

/*
[
  "char at index 0 is a",
  "char at index 1 is 🦋",
  "char at index 2 is c"
]
*/

when you have an array, you can use array methods.

• JS: Array.prototype.map
• JS: Array.prototype.forEach
• JS: Array.prototype.flatMap
• JS: Array.prototype.filter

Spread Operator

Spread Operator can be used to convert string to array of characters, or as function arguments.

• JS: Spread Operator (triple dots)

// spread operator on string
console.log([..."a🦋c"])
// [ "a", "🦋", "c" ]

Using for-loop (go thru 16-bit units)

Using for-loop is not recommended, because it goes thru code unit, not characters.

• JS: String Index and Code Unit

const xx = "a🦋c";
for (let i = 0; i < xx.length; i++) {
 console.log(xx[i]);
}
/*
a
�
�
c
*/