fetch('replace.json')
.then(res => res.json())
.then(data => {
let result = '火と水と風と火'
for (const [key, value] of Object.entries(data)) {
const reg = new RegExp(key, 'gm')
result = result.replace(reg, value)
}
document.getElementById('result').textContent = result
})
// replace.json の内容
{
"火": "fire",
"水": "water",
"風": "wind"
}