To check if a string starts with a space or not we can use: RegExptestmethod, Stringmatchmethod with regExp, or StringstartsWithmethod Let's see the above-mentioned methods with examples. Using RegExp.test() me
Returns true if the string starts with the value, otherwise it returns false JavaScript Version: ECMAScript 6More ExamplesCheck if a string starts with "world", starting the search at position 6: var str = "Hello world, welcome to the universe."; var n = str.startsWith("world", 6); ...
if(typeofString.prototype.startsWith !='function') { String.prototype.startsWith =function(prefix){ returnthis.slice(0, prefix.length) === prefix; }; } String.slice()和String.substring()类似,都是获得一段子串,但有评测说slice的效率更高。这里不使用indexOf()的原因是,indexOf会扫描整个字符串,...
If you ever need to check if a string begins with another string in JavaScript, use ES6's startsWith method...
startsWith()is not supported in Internet Explorer. JavaScript String endsWith() TheendsWith()method returnstrueif a string ends with a specified value. Otherwise it returnsfalse: Examples Check if a string ends with "Doe": lettext ="John Doe"; ...
The startsWith() method returns true if a string begins with specified character(s). If not, it returns false. Example const message = "JavaScript is fun"; // check if message starts with Java let result = message.startsWith("Java"); console.log(result); // true // check if ...
Example 1: Using endsWith() Method // string definitionletsentence ="JavaScript is fun"; // checking if the given string ends with "fun"letcheck = sentence.endsWith("fun"); console.log(check); // checking if the given string ends with "is"letcheck1 = sentence.endsWith("is"); ...
text.startsWith("Hello",1); Try it Yourself » Description ThestartsWith()method returnstrueif a string starts with a specified string. Otherwise it returnsfalse. ThestartsWith()method is case sensitive. See Also: The endsWith() Method ...
var index = input.length - string.length; // Check if the calculated index is non-negative and if the substring is found in the input string starting from the calculated index. return index >= 0 && input.indexOf(string, index) > -1; } // Test the endsWith function with a sample ...
test(string); const endsWith = pattern => string => new RegExp(`.*${pattern}$`).test(string); const sports = "🏈🎳⛳⛸"; console.log(startsWith("🏈")(sports)); // true console.log(startsWith("⛸")(sports)); // false console.log(endsWith("🏈")(sports)); // ...