how to remove last /r in javascript code example

Example 1: js remove last character from string

let str = "Hello Worlds";
str = str.slice(0, -1);

Example 2: javascript remove line breaks from string

var stringWithLineBreaks = `
O boy 
I've got 
Breaks
`;
var stringWithoutLineBreaks = stringWithLineBreaks.replace(/(\r\n|\n|\r)/gm, "");//remove those line breaks

Example 3: javascript remove all newlines

// regex global match for all variants of newlines
/\r?\n|\r/g

// example
let foo = 'bar\nbar';
foo = foo.replace(/\r?\n|\r/g, " "); /* replace all newlines with a space */
console.log(foo); /* bar bar */

Example 4: javascript remove last character from string

let str = "12345.00";
str = str.substring(0, str.length - 1);
console.log(str);