how to read a file in js code example
Example 1: read file javascript
fetch('something.txt')
.then(response => response.text())
.then(data => {
console.log(data);
});
Example 2: how to load localt ext file in js
const fileUrl = ''
fetch(fileUrl)
.then( r => r.text() )
.then( t => console.log(t) )
Example 3: how to read a file in javascript
fetch('file.txt')
.then(response => response.text())
.then(text => console.log(text))
Example 4: js read a ini file
var fs = require("fs");
function parseINIString(data){
var regex = {
section: /^\s*\[\s*([^\]]*)\s*\]\s*$/,
param: /^\s*([^=]+?)\s*=\s*(.*?)\s*$/,
comment: /^\s*;.*$/
};
var value = {};
var lines = data.split(/[\r\n]+/);
var section = null;
lines.forEach(function(line){
if(regex.comment.test(line)){
return;
}else if(regex.param.test(line)){
var match = line.match(regex.param);
if(section){
value[section][match[1]] = match[2];
}else{
value[match[1]] = match[2];
}
}else if(regex.section.test(line)){
var match = line.match(regex.section);
value[match[1]] = {};
section = match[1];
}else if(line.length == 0 && section){
section = null;
};
});
return value;
}
try {
var data = fs.readFileSync('C:\\data\\data.dat', 'utf8');
var javascript_ini = parseINIString(data);
console.log(javascript_ini['Section1']);
}
catch(e) {
console.log(e);
}
Example 5: Read files in JavaScript
function readImage(file) {
if (file.type && !file.type.startsWith('image/')) {
console.log('File is not an image.', file.type, file);
return;
}
const reader = new FileReader();
reader.addEventListener('load', (event) => {
img.src = event.target.result;
});
reader.readAsDataURL(file);
} Check if the file is an image. if (file.type && !file.type.startsWith('image/')) { console.log('File is not an image.', file.type, file); return; } const reader = new FileReader(); reader.addEventListener('load', (event) => { img.src = event.target.result; }); reader.readAsDataURL(file);}