c# if string begins with code example

Example 1: javascript check if string ends with

function endsWith(str, suffix) {
    return str.indexOf(suffix, str.length - suffix.length) !== -1;
}

endsWith("hello young man","man");//true
endsWith("hello young man","boy");//false

Example 2: javascript string starts with

//checks if a string starts with a word
function startsWith(str, word) {
    return str.lastIndexOf(word, 0) === 0;
}
startsWith("Welcome to earth.","Welcome"); //true