How to check whether a string contains a substring in JavaScript?
ECMAScript 6 introduced String.prototype.includes
:
const string = "foo";
const substring = "oo";
console.log(string.includes(substring)); // true
How to check whether a string contains a substring in Kotlin?
Kotlin has stdlib
package to perform certain extension function operation over the string, you can check this method it will check the substring in a string, you can ignore the case by passing true/false value. Refer this link
"AbBaCca".contains("bac", ignoreCase = true)
what is the best way to check if a string exists in another?
Use indexOf
:
'Hello, my name is jonh LOL.'.indexOf('Hello, my name is jonh') > -1; //true
'LOL. Hello, my name is jonh'.indexOf('Hello, my name is jonh') > -1; //true
You can also extend String.prototype
to have a contains
function:
String.prototype.contains = function(substr) {
return this.indexOf(substr) > -1;
}
'Hello, my name is jonh LOL.'.contains('Hello, my name is jonh'); //true
'LOL. Hello, my name is jonh'.contains('Hello, my name is jonh'); //true
function to check if a string contains all elements of another string
str2 in str1
check whether the whole string str2
is present as a substring in str1
. You need to iterate over str2
to check if every character of str2
is present in str1
using the all()
function.
def minSubStr(str1, str2):
str1 = input("Enter the first string: ")
str2 = input("Enter the second string to check if the characters exist in the first string: ")
if all(s in str1 for s in str2):
return True
return False
How to check if a string contains a substring in Bash
You can use Marcus's answer (* wildcards) outside a case statement, too, if you use double brackets:
string='My long string'
if [[ $string == *"My long"* ]]; then
echo "It's there!"
fi
Note that spaces in the needle string need to be placed between double quotes, and the *
wildcards should be outside. Also note that a simple comparison operator is used (i.e. ==
), not the regex operator =~
.
How to check whether a string contains a substring in Ruby
You can use the include?
method:
my_string = "abcdefg"
if my_string.include? "cde"
puts "String includes 'cde'"
end
How do I check if a string contains a specific word?
Now with PHP 8 you can do this using str_contains:
if (str_contains('How are you', 'are')) {
echo 'true';
}
RFC
Before PHP 8
You can use the strpos()
function which is used to find the occurrence of one string inside another one:
$haystack = 'How are you?';
$needle = 'are';
if (strpos($haystack, $needle) !== false) {
echo 'true';
}
Note that the use of !== false
is deliberate (neither != false
nor === true
will return the desired result); strpos()
returns either the offset at which the needle string begins in the haystack string, or the boolean false
if the needle isn't found. Since 0 is a valid offset and 0 is "falsey", we can't use simpler constructs like !strpos($a, 'are')
.
How can I check if a string exists in another string
Use String.Contains:
if (stringValue.Contains(anotherStringValue))
{
// Do Something //
}
Check if a string contains another string
Use the Instr function (old version of MSDN doc found here)
Dim pos As Integer
pos = InStr("find the comma, in the string", ",")
will return 15 in pos
If not found it will return 0
If you need to find the comma with an excel formula you can use the =FIND(",";A1)
function.
Notice that if you want to use Instr
to find the position of a string case-insensitive use the third parameter of Instr and give it the const vbTextCompare
(or just 1 for die-hards).
Dim posOf_A As Integer
posOf_A = InStr(1, "find the comma, in the string", "A", vbTextCompare)
will give you a value of 14.
Note that you have to specify the start position in this case as stated in the specification I linked: The start argument is required if compare is specified.
How do I check if a string contains another string in Swift?
You can do exactly the same call with Swift:
Swift 4 & Swift 5
In Swift 4 String is a collection of Character
values, it wasn't like this in Swift 2 and 3, so you can use this more concise code1:
let string = "hello Swift"
if string.contains("Swift") {
print("exists")
}
Swift 3.0+
var string = "hello Swift"
if string.range(of:"Swift") != nil {
print("exists")
}
// alternative: not case sensitive
if string.lowercased().range(of:"swift") != nil {
print("exists")
}
Older Swift
var string = "hello Swift"
if string.rangeOfString("Swift") != nil{
println("exists")
}
// alternative: not case sensitive
if string.lowercaseString.rangeOfString("swift") != nil {
println("exists")
}
I hope this is a helpful solution since some people, including me, encountered some strange problems by calling containsString()
.1
PS. Don't forget to import Foundation
Footnotes
- Just remember that using collection functions on Strings has some edge cases which can give you unexpected results, e. g. when dealing with emojis or other grapheme clusters like accented letters.
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