javascript index of string code example

Example 1: javascript index of with var

var indices = [];
var array = ['a', 'b', 'a', 'c', 'a', 'd'];
var element = 'a';
var idx = array.indexOf(element);
while (idx != -1) {
  indices.push(idx);
  idx = array.indexOf(element, idx + 1);
}
console.log(indices);
// [0, 2, 4]

Example 2: javascript indexof

//indexOf getting index of array element, returns -1 if not found
var colors=["red","green","blue"];
var pos=colors.indexOf("blue");//2

//indexOf getting index of sub string, returns -1 if not found
var str = "We got a poop cleanup on isle 4.";
var strPos = str.indexOf("poop");//9

Example 3: indexof javascript

//indexOf - JS method to get index of array element. 
// Returns -1 if not found

var colors=["red","green","blue"];
var pos=colors.indexOf("blue");//2

//indexOf getting index of sub string, returns -1 if not found

var str = "We got a poop cleanup on isle 4.";
var strPos = str.indexOf("poop");//9

//Eg with material ui

<Checkbox
   checked={value.indexOf(option) > -1}
   value={option}
/>

Example 4: js find index of string in string

// Find the index of a string in a given sentence
function findNemo(sentence) {
	let indexOfFirst = sentence.split(' ').indexOf('Nemo') + 1;
	if(indexOfFirst >= 0){
		return `I found Nemo at ${indexOfFirst}!`;
	}
	return ("I can't find Nemo :(");
}


console.log(findNemo("I am finding Nemo !"));   //"I found Nemo at 4!"
console.log(findNemo("Nemo is me"));            //"I found Nemo at 1!"
console.log(findNemo("I Nemo am"));             //"I found Nemo at 2!"

Example 5: js indexof string

str.indexOf(searchValue[, fromIndex])

Example 6: indexof javascript

Array.indexOf(searchElement, fromIndex)