1. indexOf
inputStr.indexOf(str) - returns first occurrence of mentioned str in given inputStr
inputStr.indexOf(str, 10) - returns first occurrence of string after 10 position.
const str = 'Hi, Welcome to Vishwaks JS articles';
str.indexOf('Welcome');
> 4
str.indexOf('Welcome', 10); // Search after 10th position.
> -1
const str = 'Hi, Welcome to Vishwaks JS articles - Welcome to JustCode';
str.indexOf('Welcome', 10); // Search after 10th position.
> 38
str.indexOf('hi'); // case sensitive
> -1
2. lastIndexOf
Same like indexOf but searches from end of the string.
inputStr.lastIndexOf(str) - returns last occurrence of mentioned str in given inputStr
inputStr.lastIndexOf(str, 10) - returns last occurrence of string from 10 index to beginning.
const testString = "locate string locate";
testString.lastIndexOf('locate');
> 14
testString.lastIndexOf('locate', 14);
> 14
testString.lastIndexOf('string');
> 7
testString.lastIndexOf('string', 6);
> -1
testString.lastIndexOf('string', 15);
> 7
testString.lastIndexOf('String'); // case sensitive
> -1
3. search
search() is same like indexOf but won't allow position param.
Whereas, indexOf won't support regex based search but search() supports it.
const str = 'Hi, Welcome to Vishwaks JS articles 1234';
str.search('Welcom');
> 4
str.search(/\d/);
> 36
str.search(1234);
> 36
str.search('welcome'); // case sensitive
> -1
4. match
match() searches specified string same like search but returns an array of matched strings.
const str = 'Hi, Welcome to Vishwaks JS articles 1234';
str.match('Hi');
> ['Hi', index: 0, input: 'Hi, Welcome to Vishwaks JS articles 1234', groups: undefined]
str.match('Welcome');
> ['Welcome', index: 4, input: 'Hi, Welcome to Vishwaks JS articles 1234', groups: undefined]
str.match(/\d/);
> ['1', index: 36, input: 'Hi, Welcome to Vishwaks JS articles 1234', groups: undefined]
str.match('hi'); // case sensitive
> null
5. includes
includes() returns true if string found.
const str = 'Hi, Welcome to Vishwaks JS articles 1234';
str.includes(1234);
> true
str.includes('JS');
> true
str.includes('test');
> false
str.includes('hi'); // case sensitive
> false
6. startsWith
Returns boolean if string starts with specified value.
str.startsWith('test') - if 'str' starts with 'test' then returns true otherwise false.
str.startsWith('test', 10) - 10th index in string starts with test or not.
const str = 'Hi, Welcome to Vishwaks JS articles';
str.startsWith('Hi');
> true
str.startsWith('Welcome', 4);
> true
str.startsWith('hi'); // case sensitive
> false
7. endsWith
Returns boolean if string ends with specified value.
str.endsWith('test') - if 'str' ends with 'test' then returns true otherwise false.
str.endsWith('test', 10) - till 10th index in string ends with test or not.
const str = 'Hi, Welcome to Vishwaks JS articles';
str.endsWith('articles');
> true
str.endsWith('to', 14); // Check first 14 characters ends with to.
> true
str.endsWith('aRticles'); // case sensitive
> false
There are two more methods which are from RegExp are test() & exec() does the same.
All the above methods are case sensitive methods.
Thanks,
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