JSFiddle - React, Tailwind, and code Playground

JavaScript

var size = 7;
var half = Math.floor(size / 2);
var txt = '';
for (var i = 0; i < size; i++) {
    for (var j = 0; j < size; j++) {
        var isOne = (
            (i + j < half) || 
            (j - i > half) || 
            (i - j > half) ||
            (i + j > size + half - 1)
        ) 
        txt += isOne ? '1' : '0';    
    }    
    txt += '<br>'
}
document.body.innerHTML = txt;