JS中20个常用字符串方法及使用方式（总结）

//search(regexp)

var intRegex = /[0-9 -()+]+$/; 

var myNumber = '999';

var isInt = myNumber.search(intRegex);

console.log(isInt);

//output: 0

//slice(start, end)

var text="excellent"

text.slice(0,4) //returns "exce"

text.slice(2,4) //returns "ce"

//substring(from, to)

var text="excellent"

text.substring(0,4) //returns "exce"

text.substring(2,4) //returns "ce"

//substring(from, [to])

var myString = 'javascript rox';

myString = myString.substring(0,10);

console.log(myString)

//output: javascript

//toLowerCase()

var myString = 'JAVASCRIPT ROX';

myString = myString.toLowerCase();

console.log(myString)

//output: javascript rox

//toUpperCase()

var myString = 'javascript rox';

myString = myString.toUpperCase();

console.log(myString)

//output: JAVASCRIPT ROX

//includes()

var mystring = "Hello, welcome to edureka";

var n = mystring.includes("edureka");

//output: True

//endsWith()

var mystr = "List of javascript functions";

var n = mystr.endsWith("functions");

//output: True

//repeat()

var string = "Welcome to Edureka";

string.repeat(2);

//output: Welcome to Edureka Welcome to Edureka

//valueOf()

var mystr = "Hello World!";

var res = mystr.valueOf();

//output: Hello World!

//trim()

var str = "     Hello Edureka!     ";

alert(str.trim());