Get Programming with JavaScript - Listing 7.09

Get Programming with JavaScript - Listing 7.09

Listing 7.09 - Finding a character with indexOf

var message = "We choose to go to the Moon!";

var charIndex = message.indexOf("M");

console.log(message.substr(charIndex, 3));

Further Adventures

Listing 7.09 - Finding a character with indexOf - Task 1

Use indexOf to find the index of where the word 'go' starts in the message string.

var message = "We choose to go to the Moon!";

var charIndex = message.indexOf("g");

As the g in 'go' is the only one, you can just search for 'g'.

Listing 7.09 - Finding a character with indexOf - Task 2

Use indexOf and substr to display the word 'choose' from the message string.

var message = "We choose to go to the Moon!";

// Find where the word starts
var charIndex = message.indexOf("c");

// Display 6 letters - the whole word
console.log(message.substr(charIndex, 6));

Listing 7.09 - Finding a character with indexOf - Task 3

Use lastIndexOf to find the index of the 'oo' in the word 'Moon' of the message string.

var message = "We choose to go to the Moon!";

var charIndex = message.lastIndexOf("oo");

Both 'choose' and 'Moon' include the string 'oo'. lastIndexOf will find the last one in the message, i.e. the 'oo' in 'Moon'.