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Javascript function to filter a an array of strings based on starting letters of the strings in the array

I need help writing a Javascript function which will take a string as an arugment and then filter out an array of strings starting with the string I pass as an argument.
So if I have the following array:
let words = ['simple', 'single', 'side', 'sacked', 'apple', 'orange']
I need a javascript funtion that will look at every string in this array, and give me a second array called myFilteredWords which start with the letters 'si" - assumuming that I pass 'si" as an argument to the funtion.

zc2

Like this?

function f( s, a ) {
    var sl = s.length;
    var na = [];
    for( var i in a )
        if( a[i].substr( 0, sl ) == s )
            na.push(a[i]);
    return na;
}

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ASKER CERTIFIED SOLUTION

Julian Hansen

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SOLUTION

Norie

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Eddie Shipman

Give this a try:

var words = ['simple', 'single', 'side', 'sacked', 'apple', 'orange'];
const regex = new RegExp('^si', 'g')
const myFilteredWords  = words.filter(value => regex.test(value));
console.log(myFilteredWords);

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Julian Hansen

startsWith() does not appear to be supported on IE

Norie

Julian

I think you are right, it's not supported in IE11 anyway - not sure about other versions.

FaheemAhmadGul

ASKER

Many thanks all the experts for your comments. As both Julian's and Norie's solutions were most helpful and I accepting both. Hope this is OK.

Julian Hansen

You are welcome.