Answers for "javascript check if a string contains certain characters"

23

check for substring javascript

const string = "javascript";
const substring = "script";

console.log(string.includes(substring));  //true
Posted by: Guest on July-06-2020
9

javascript check if character exists in string

// With ES6 MDN docs .includes()
"FooBar".includes("oo"); // true
"FooBar".includes("foo"); // false
"FooBar".includes("oo", 2); // false (2 is the start position for the search)

// E: Not suported by IE - instead you can use the Tilde opperator ~ (Bitwise NOT) with .indexOf()
~"FooBar".indexOf("oo"); // -2
~"FooBar".indexOf("foo"); // 0
~"FooBar".indexOf("oo", 2); // 0 (parameter 2 is the start position for the search)

// Used with a number, the Tilde operator effective does ~N => -(N+1). Use it with double negation !! (Logical NOT) to convert the numbers in bools:
!!~"FooBar".indexOf("oo"); // true
!!~"FooBar".indexOf("foo"); // false
!!~"FooBar".indexOf("oo", 2); // false
Posted by: Guest on August-05-2020
29

javascript check if string contains character

var str = "We got a poop cleanup on isle 4.";
if(str.indexOf("poop") !== -1){
	alert("Not again");
}
//use indexOf (it returns position of substring or -1 if not found)
Posted by: Guest on July-18-2019
6

js check if string contains character

"FooBar".includes("oo"); // true

"FooBar".includes("foo"); // false

"FooBar".includes("oo", 2); // false
Posted by: Guest on June-12-2020
0

js check if string contains character

if (your_string.indexOf('hello') > -1)
{
  alert("hello found inside your_string");
}
Posted by: Guest on June-12-2020

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